This is a rough one, trying to figure all of this out. Could you possibly be ovulating late and the sore breasts are happening during the normal cycling of hormones? Or have you just not triggered a pregnancy test yet? I would imagine that they will first give you a urine pregnancy test at the doctor and then consider the blood test. It's a tough time for going to the doctor right now unfortunately. I think though that a blood test would indicate any HCG at all in your blood.
One thing that I found really helpful was temperature taking. You take it first thing in the morning, every morning and chart it. you'll start to notice a pattern. The beginning of your cycle, you'll have a specific temperature and then once you have ovulated, it goes up one full degree. It stays high until the day you start your period or the day before that and then it drops back down the degree . . . UNLESS you are pregnant, and then it stays high. Mine stayed high twice, both times pregnant. It's really good for an extra piece of information.
So, what day are you on exactly now? I am trying to figure that out.