maybe just paranoid, but...

Okay, I will admit my body is a bit of a roller coaster at the moment. I got off depo last May, got my first period in August and it took 45 days for my next period, then 33. So...I have a Marathon to run Saturday and I just had some light spotting. Was feeling super mild cramps on my left side. Chances I'm pregnant and chance running 26.2 slightly competitively is a really bad idea if I am? I trained so hard!