Disrespectful partner😩

I’ve been really reluctant to post this as I really didn’t want to read other people talking against my partner in a negative way but I need to get this off my chest. I am 7 weeks pregnant and we are both happier than ever. I have been feeling unwell most days but nothing major, all as expected. My boyfriend decided to go for drinks with his friends at their house on Friday which is fine. I waited at his mums house as he told me he wouldn’t be too late as I said I would pick him up and then drive us both back to my house after I get him which is like 20 mins away. (We both expected around midnight). He asked how I was feeling during the night to which I replied “a little shitty but I’m okay” as I didn’t want to mither him or ruin his night. I then fell asleep on his mums sofa as I was just exhausted. She told me to get in bed and he can just let himself in and told me that it wasn’t a good idea to pick him up and drive to my house as I was so tired. I agreed and got into bed. I wake up at around 2:30 and he still isn’t home and I don’t have a text/missed call. I text him asking where he is and he says he’ll be home soon. (That never means soon). I was upset at this as he still expected me to get him and drive him to my house to which I told him he can let himself in and we’re staying here as I’m not going anywhere! He orders a taxi and comes home for around 3am. I ask him if he’s touched cocaine as he’d been out since 2pm, he swore on our unborn babies life he didn’t to then later admit that he did. Not only was I hurt by 0 communication, I had to deal with the lies and then the fact he’d been on drugs all night while I’m sacrificing everything lying in bed in pain worrying about him trying to sleep. What would you do in this situation? It’s the first time something like this has happened and I don’t want to ruin the relationship or take any drastic measures but I want to feel sane when he goes out rather than thinking I’m going crazy. Please help