Could I be pregnant?? Help please.?

So I got my period around may 9th, like that's when it finished. I never get my period twice in one month. Then 18th I had sex, and we used the pull out method and it got everywhere all over my thighs and all over everything. it soaked my thong. Then I got my period yesterday, the 29th. And it's different than usual. It's darker and lighter. I don't know if I'm pregnant or not. because I read you can get bleeding 6-12 days after intercourse because the baby is getting planted in or whatever...Please help. I'm so confused, and I'm peeing more often and my boobs are more sore, and I'm getting alot of headaches, Help please!!