Second trimester sex

I am 17 weeks pregnant and my husband and I have been struggling to have sex. Every time he goes inside of me it feels swollen and tight and like there is chaffing. We have tried lube, different positions, and modifying depth, but nothing has helped. The past feel weeks I have had to ask him to stop each time because it is so painful. Luckily he is very understanding. Has anyone else had an issue like this? And if so, have you found anything that helps? I have a pretty strong sex drive, but as soon as we try to have sex I am in pain! I'm desperate for a solution!