Pregnant?

Bf and I had drunk unprotected sex 13 days ago and I might be pregnant. I know it's too early but since we did it i became lactose intolerant and have a lot problems with stomachache(supposed to start period in 15 days, ovulation 5th til 12th January). I feel weird whole time and am quite dazed. Symptom of possible pregnancy or just classic sick? Advices? Thank you in advance