Hi.
A bit of backstory, I'm 6 months pregnant and have only been with my partner about a year. We moved very fast and moved in after I found out I was pregnant and decided we wanted to go ahead with the pregnancy. So before I met my partner, he told me about some drug use he had done in the past (cocaine), we spoke about this soon after meeting and I told him I've never been drug user and preferred to be with someone who didn't do drugs. He assured me this was all in his past and it was recreational so there was no problem with stopping. Ok fine. I also know his sister, through a mutual friend. We sometimes would see each other at parties and it became known to me that she was a cocaine user. Not my problem. So about a month ago, I was at a family members house and my boyfriend had arranged to pick me up. I called him and his sister answered the phone. I found this odd as he never told me she was coming over. No problem. He comes and gets me and we get back home. It's weekend so they are having a drink all fine. I went into my room as I wasn't feeling too great and just wanted to lay down. This is where the problem starts. He comes into the bedroom and tells me I'm making his sister feel very uncomfortable and not wanted as I wasn't sitting with them and went straight it to my room. I came out of my room and explained to them both why I was feeling this way. As I done this, I noticed that my boyfriend didn't look right. His pupils were very dilated and he was talking very fast. I of course asked him if he had taken any drugs. He said no. I explained to him how disgusted and upset I would be if he had done that around me and in my house. He denied it. I had no proof so I left it. A few days after something didn't seem right to me so I went through this phone and saw text messages from him and his sister talking about buying coke that night. I went ballistic and told him to leave my house. I stupidly decided to give him another chance after begging and pleading.
That brings up to this weekend. So my boyfriend works six days a week, Saturday night is his only night off. He works nights. So he woke up about 4pm and said let's do something and get out of the house as he wants to enjoy his night off. As we were deciding what to do, he calls his sister and invites her over to my house. I asked him why did he this as I don't feel comfortable having her around as I believe they will want to do drugs together. He says okay fine. Leaves me at home and goes to meet his sister. I 100% know this was to do cocaine. I've realised him and his sister aren't very close and only really see each other when they go drugs together. Evening comes and he starts texting me things about me being suspicious. He seemed paranoid which I believe was due to the cocaine. I have no proof this time but i can almost bet on my life that I am right. I told him I no longer want to be with him, I stupidly believed him when he told me he doesn't do it anymore. I've told him his mum can come get his stuff this week and I will contact him only in regard to the baby. Was I overreacting ?