Are Dark Brown Blood With Partial Clots Called Menses?

Hi I am 18 years old 5'9 and weigh 164 pounds. Me and my boyfriend have been havin unprotectrd sex but I am on birth control. There was some days where I forgot to take my pill and took it as soon as I remembered. Anyways I always start my period on Sunday and i started Saturday. I am also not sure if it is my period. It's dark brown and I have partial blood clots. today, monday, it is not a constant flow annd looks to mr as a brown discharge. I was wondering if I was pregnant or askin flifbsomethings wrong. I also have minor cramps on my lower stomach as well. Please let me know! Thank you!