Dont know what to think

Ok so here the story. I used to be really thin and recently gained alot of weight belly boobs and thighs, I put this down to either prenatal vitamins or my new depression meds. We have been trying for a year. My bf just brought up how its weird how I've gained alot on my belly because it does honestly look like a bump. I've has regular periods all this time but my last one was a bit different. Normal for 2 days then off for a day and back lighter for 3. Hea convinced I'm pregnant and just going to drop one day.