Is There Any Medicine To Induce Periods?

Hi, my last 3 months period was on 17/02, 14/04 & 11/05, and my period normally last for 5 to 7 days, whereby it had a bit by bit period from the 4 days onwards and it last till the 7 days.. And i had unprotected sex with my bf on 22/05. And my worries is my period is not here yet till now? Any chance of pregnancies? And is there any medication that i can take to induce my period?