i think i may be pregnant

I have been on dianette contraceptive pill for a while now. Last week i forgot to take a few pills and had unprotected sex. the pills i forgot to take were in the first week, so im worried that i may be pregnant. my period isnt due for a few weeks yet. I just am not sure whether to carry on taking the pill or stop taking it until i no if i am or i am not?
I have got pregnant before whilst on dianette a year and a half ago but i misscarried.