Please help me...please

I've said for the past days that I'm not sure if I've been having implantation bleeding or my period. My s/o has talked to his doctor, his mother, and ive gotten feedback from people here BUT IM NOT CONVINCED. I feel so awful and afraid because I know I'm not ready to have a child of my own. My period was 8 days late, I mean I don't even know what I had this week was even a period. I had terrible cramps that I couldn't lay down but I was only able to sit up. This lasted like 2-4 hours. Then I got bleeding but it was right red/pink. At first it wasn't a whole lot (this whole week was really light and I'm usually a heavy flow) but by the 2nd day there was a time where it was "normal" flow kinda. The third day was light, the 4th day was light but again "normal". Fifth day was very light like the blood was only a size of a half dollar, then 6th day (today) there was brown/black but it was like all over the pad not like a line or anything. I'm really nervous. Many people have told me that I'm fine, but I don't understand. Is it because of stress? I was stressed a week before this happened due to school, family, friends and stuff. Then igot more stressed and anxious when I realized my period was late. I haven't stopped crying since last Thursday. The reason why I'm so afraid is because there had been occasions where my S/O and I would foreplay. I mean we weren't naked at all, but I still touched him. I touched his genitals while he still had his boxers and his sweats on, I don't know if I ever had sperm on my fingers. Probably like 5 minutes after that I would go home ya know. And like once I get home I would finger myself with the same hand, unintentionally. I'm not sure if I'm okay. I'm trying to be the most descriptive as possible. I really want to know if I'm okay..to add on I'm overweight, I'm also anemic so I don't know if that could also be a reason why my period was delayed? Or was it because of stress? Or am I possibly pregnant...please let me know this has been eating me alive for the past week. I haven't been sleeping, only less than 6 hours of sleep I've been getting and I'm tired of crying and worrying..please let me know and bless your souls for helping me out this is something that I'm so afraid about..please give me an explanation on what's going on with me. I've been so stressed out over this and it's ruining everything about me..