Period, stomach aches, pains in stomach, bleeding massively.

About month ago and some odd days, I had to switch new birth control cos of my doctor. They said wait a week until having sex again. 5 days later me and my fiance had sex. Then, after starting my new birth control for about a week. I lost the packet and started takin my old birth control which was still in good use, not too old. That lasted 2 weeks. Yesterday i stated to take my new birth control again cos i found it. But 2 weeks ago after starting my old birth control again i had massive bleeding, brown, non odor comming from my vagina for about 7 days and stomach pains. During the bleeding i had few odd cramps. But now, my stomach still hurts everyday for atleast a few hours . Am i pregnant? Please let me know whats going on, anyone.