Confused (A.I.P?)

I had sex on my menstrual last Tuesday (it was lighter by then), 3 or 4 days before it ended (it ended on Friday), and we used a condom. Now a week later, I had a small flow of watery, thin blood that stained my underwear. I always have what seems to be an excessive amount of discharge, but this bleeding is abnormal. I had been constipated and gassy for weeks (way before the sex), and today all of a sudden my bowels are moving. I can't tell if I'm nervous and nauseous out of a pregnancy fear, or if my organs are upset from the bowel movements, or pregnancy.

My periods are usually very heavy, with violent backaches and cramps, and these past few months I've been very weak and fatigued, regardless of whether or not I'm on my period. I've been having alot of pain in my ovary area, and what feels like lymph node pain (swollen and sore) in the crease between my pubic mons and thighs. My mother has had uterine fibroids, and I have yet to get to a doctor to see if I have them too. Considering all of this, could I be pregnant?