I am bleeding, could I possibly be pregnant?

Patient: Am I possibly pregnant? I had unprotected sex on Aug. 27. I was supposed to get my period on Sep. 10 but got in on Sep. 5 instead. I am normally very heavy but I did notice however that that period was slightly lighter. It was bright red, had blood clots, flow and lasted for 5 days(I’m sorry for being too graphic, I feel I need to be clear and detailed). I was also experiencing severe cramps that lasted 3 days all day, when I normally get them for just the first day. I did research on the internet and thought maybe it might have been implantation bleeding and my body could just be acting differently. I took 2 home pregnancy test which came out negative. I felt better once I got the negatives and continued with my daily life, but 2 days ago I got my period again right on time on Oct. 6, but I normally feel when I get my period, I feel the cramps and the flow of when arrives, this time I felt nothing on the first day, I put a pad and it was a small amount of brown blood. Yesterday morning I finally had stained a pad but felt no flow, the only times I felt flow was when I went to the bathroom. It is bright red and I do have some blood clots, it was also yesterday that I felt cramps. The strange thing about my period is that it is very light, even lighter than last months and I see brown blood mixed with the bright dark red blood. I have been feeling a little tired and have felt lightheaded at times. I have no other symptoms, no nausea or sore breasts. I once agian did research online and say that many women can still have vaginal bleeding even if they are pregnant. I would really appreciate a reply back. I have no insurance and am a current college student. My parents are very religeous and would not be happy ifI were pregnant at this point in my life. Thank you for your time and any help you could give me.