I have ER+ Breast cancer and I am 16 weeks pregnant:Please help

My name is Benny, I am 43 yrs old. I first noticed nipple retraction and  inversion  of my right breast during the breastfeeding of my second daughter around  September 2011. I reported to my O & G and after looking at it he said it was nipple inversion. He suggested that I may need to get nipple retractor device and he also advised me to be pulling out the nipple from time to time. Since I have reported to a doctor, my mind was off the incidence. Infarct breast milk gradually stopped coming out from the right breast. My daughter only sucked the left breast until she stopped breast-feeding. However, with time around the tip of my right breast appeared to have small lump, however, I thought the milk gland had congealed and hence the lump. I could remember I went to my O & G and in his usual way he dismissed my fear. However in the month of may 2013, I became pregnant. Infarct, my last menstrual period was on 4^th may 2013. I now decided to change my O&G and therefore I registered under another O&G. he also performed preliminary physical examination. I drew his attention to the breast lump, he looked at it and again in the doctor’s manner did not comment badly on it. i told him that in my second pregnancy, my former O&G placed on xx injection to stabilize the implantation of the fetus. So this second O&G also decided to give similar injections. I stated the injection on 1^st June 2013 and had my 5^th doze on first week of july 2013. However, as I was not comfortable with the nature of my right breast, I voluntarily decided to go for breast screening in a local center. It was there that the doctor at the center referred me to a teaching hospital for proper evaluation.

At the teaching hospital, I consulted a surgeon. When the doctor saw the lump, he shouted and referred me immediately for histological evaluation. Fine needle aspiration was done in which some samples of my breast tissue was taken for histology and EP/ER/HER2. The histology result came out a week after with bad news. I was  diagnosed of invasive ductal carcinoma, classic variant with the following histological report:

1. Microscopic examination: Sections show infiltrative malignant epithelial proliferation within the breast parenchyma. The constituent cells are arranged in wide solid islands, broad anastomosing trabeculae, thin cords, glandular structures and individual infiltrating cells. The cells have irregular hyperchromic nuclei. The tumors show moderate tumor necrosis. There is moderate stromal fibrosis and mild chronic inflammatory infiltrate in response to the invading tumor cells. The tumor is seen invading the skeletal muscle (pectoralis) and the base of the biopsy.
2. Diagnosis:

                    I.            Breast: invasive ductal carcinoma, classic variant

                  II.            TNM staging: Pt4pNxpMx

1. Pathologist’s recommendation: Urgent mastectomy

I was then referred to oncology unit and also to ante-natal clinic  for evaluations. Both clinics requested me to do series of blood tests, 2-D Echo, etc.  The oncologist decided to wait until my 14 weeks gestation age before he would  commence treatment. After 14 weeks I was started on chemo on 9^th August, 2013 with the following Rx:

1. CHEMO> IV: Cyclophosphamide 1160 mg and IV: Adriamycin 115mg
2. PREMED> IV: Ondasteron 10mg, IV: Dexamethasone 8mg and  IV: Plasil 8mg
3. POSTMED: Tabs: Dexamethasone (5 days), Tabs: plasil (5days), tabs: Fesolate and Vit C (2wks)

On 15^th August 2013 the EP/ER/HER2 result came out with the following result:

1. Esterogen Result (POSITIVE): Intensity of staining (2), % of positive tumor cells (3), Quick score (5)
2. Progesterone result: Negative
3. Her-2: Negative

I am due for the next chemo on 30^th August 2013. BUT I AM CONFUSED!  I called the oncologist about his opinion on ER+ result in a pregnancy of 16wks. He said he might introduce TAMOXIFEN, but he said he want to send the specimen block to another laboratory for a second opinion lab test. The big question is:

1. Do we have to terminate the pregnancy at this stage since due to ER+ status?
2. If Taxomofen will be used, is it safe for the baby?
3. What other options do we have?

Please I need you help and advice here and urgently too. Also if you can link me to any person who have similar experience I will be very grateful.