I've Had Unprotected Sex With My Boyfriend Three Times In

I've had unprotected sex with my boyfriend three times in the past two weeks. I have recently got off my birth control maybe four weeks ago. I don't know if I may be pregnant or not and want to know if some of my symptoms might say I am. I'm hungry a lot like all the time, very tired and occasionally get lightheaded. I started spotting two days ago and also had some cramping it got heavier though the day then was light again. This is the third day I've had this light period like thing. I'm not suppose to start till next week. I don't know if it's a possibility that I might be pregnant. I took three tests and they've all said negative..I don't know what to do.