Am i pregnant?? HELP!

My bf and i had sex on Jan. 15 and i was 2 days away from ovulating. We used a spermicidal condom and he pulled out when he came. After that i was suppose to have my period near end of the month. I spotted but there was no period. I was 8 days late until i masturbated using a dildo last night then got my period early this morning or sometime last night (Feb. 5). It's a dark red though and it was kind of watery. I've gained weight and when i press on my abdomen harshly it hurts but it could be my intestines and other organs. Im paranoid about being pregnant bc i heard of a girl having her regular periods but was pregnant and didn't even know it. How can i self check? Im not experiencing and pregnancy symptoms.