I had sex and he used a condom and i am on the pill. it was also during my period. i'm a worrier and wonder if i should worry about pregnancy.

Yes, Always: All methods affect odds but never guarantee results. Methods are reported, analyzed as events/odds-by actual rates of occurrence: historic event rates for those sampled and the methods used. However, these are typically reported using the misleading term "risk" which assumes history will repeat itself, future groups match and future issues are identical.

Anxiety a problem : Given all the facts which are against the likelihood of pregnancy, it sounds as though a larger issue is that of anxiety. You might benefit from a discussion of your concerns with your gynecologist and with a therapist.