freaking out

This result is common.  2+  is on a scale, it doesn't mean the same as simply saying "positive." 

Lots of things in medicine are graded as 0 (not present), 1+ (a little), 2+ (more) 3+ (a lot).  It's a very vague way of describing something. The 2+ means you had some, but not a lot, of HER2 expressed on your cells.  It's my understanding that a huge number of cancers have a small-medium amount of HER2.  3+ would mean you had a lot, and I don't know if they'd even need to do the FISH, which is a different kind of test.  If you have a 2+ (medium) amount on the cells and are FISH negative, that qualifies you as "HER2 negative" when those terms are used to determine if  Herceptin is to be used.  At this point, cancers with this pattern do not qualify for Herceptin treatment (except in a clinical trial).  

In a way, it's kind of like saying ER+ or ER-, when really the situation is more complicated.  Some tumours are only 10% ER+, some (like mine) pretty much entirely ER+, but those nuances get lost when the description of the tumour characteristics gets shortened. 

I hope this is helpful.   

That's right.

50% of BC is Her 1+ or Her 2+, which is still considered "Her negative" even though it is really in actuality "low Her."

Only 25% is Her 3+ which is considered "Her positive" and currently eligible for Herceptin.

There is a clinical trial right now testing whether Herceptin also works on and is warranted for Her 1+ and Her 2+.