don't know what to think ...

Hi guys,

Just after a bit of advice. Sorry if too much info.

My last period was on the 21st of Feb making me due around the 19/20th of this month. A few days before I had a bit more discharge than normal and when I wiped there was a bit of tiny bit of blood and this lasted for about 2 days on and off. I've been making regular trips to the loo, keep bloating, a lot more tired than usual and I can't get worm. My boobs don't hurt but do feel a lot more bigger than normal.  I have taken 2 home pregnancy tests that had both come back negative. The only reason that's making me think that I am not is that my partner had a vasectomy nearly 4 years ago and I haven't been with anyone else. I just don't know what to think.