No Sex drive! Please help

I have been with my SO for 2yrs and we have a 1yr old together and i am now pregnant with our second child. Ever since i got pregnant with our first I have had little to no sex drive at all. It has put a lot of strain on our relationship and he thinks I’m no longer attracted to him (even tho i think he’s the most handsome man in the world.) I have tried looking things up and talking to friends about what I can do to boost my libido. I’m only 23 and I can only feel like something is wrong with me to not want to when he does. I can go weeks/months without even thinking about it, the only reason it’s ever in my mind is when he brings it up and is upset because again I’m “not in the mood.” He isn’t the type to go cheat, but I still worry, with it putting such a strain on our relationship, that we will end up splitting somewhere down the road. For the most part, this is our only roadblock so far in our relationship and I’m trying so hard to figure out what i can do to fix this and make him happier. I’d hate to go to a doctor, so I’m turning to you all. Help please!