Am I pregnant?

Okay so I am on birth control and I take it everyday. I did miss one pill I think the first one of my pack. I've been having sex with my ex boyfriend(I'm aware I'm an idiot for that) and he pulled out most of the times except for like one or two times. I don't get my period for a week but I've been getting these weird cramps like similar to period cramps. I've never experienced cramps the week before my period. I also have had some lower back pain randomly and my nipples have been so so so sore. I've felt kind of off and tired the past few days. I'm waiting until my period is late to take a test so I get the best result but do you think I could be pregnant? I've been looking into it and my symptoms match being pregnant. Anyone have any advice or knowledge or have previous experience in being pregnant. I'm nervous and have only talked to one person about it because I don't want to bring it up to my ex yet until I know for sure.