bladder infection or pregnant?

Jessica
I am about 12 dpo today and my period is due in 2 days. I never actually got my peak from my OPK, but I did get a high reading for a few days. We had sex on cycle day 12 and 14 and glow says I should have ovulated on day 15.
Last week I had some very light cramps for about two days and then my uterus felt very heavy after that for another two days. Today I feel like I have the constant need to pee.
I don't have any burning or itching or any other discomfort.
I took a test on Saturday (probably too early, but I was going out for a friends bday and wanted to see if I should obstain from having a few drinks) and it was a BFN.
Has anyone else had this sort of thing happen?