Idk what to do..

So my fiance and I have been together for 3.4 years and I am 21 weeks pregnant. In the beginning of our pregnancy we lost someone dear in our family that took a huge toll on my fiance. We lacked affection during this stressful time. From about week 5-17 we didn't have sex at all but now I've literally been begging him for sex and he turns me down. It's been 2 weeks since we were last affectionate. Last night I put on something sexy after a shower and he declined my advances. I cried in the bathroom because I feel like he's not interested in me anymore.

I trust him completely and I do random phone checks and never found anything besides a porn video he might've downloaded... Idk what to do anymore