<human>: Can you condense the text into a few key points?

I am a female, early twenties. My S.O. and I have been together several years and are very close, 100% comfortable with each other, live together, very much in love and happy. 

I am struggling with whether or not to tell him that I've been re-visited by a past trauma. I suffered from a sexual assault a few years before I met him. After it happened I had nightmares about it every night until a few years of us being together. (I credit him with getting rid of them, although I don't think I've ever said that directly to him.) 

Now I've been having the dreams again on a nightly basis. I feel like I should confide in him, but I don't want him to feel bad. He has enough going on right now to worry/stress about and I feel like I already ask too much from him on a daily basis. (I'm pregnant so I need help with many small things, nothing majorly difficult or time consuming.) 

I don't know what good it would even do to tell him, it's not like he can do anything to stop it from happening. It seems like I'd be putting him through something for no reason even though it'd probably be nice to talk to him about it. I don't want to be selfish, but I also feel strange about keeping something from him.
<bot>: Having nightmares about something that happened in my past, don't know if I should tell my SO about them or not.