How often do you have sex a week whilst pregnant?

I’m asking this because when I was pregnant with my son, we weren’t allowed to have sex due to complications I had towards the end of my pregnancy.

I am currently 28 weeks pregnant with my second baby and I cannot remember the last time we had sex. We are both in our early 20’s and my mum is always saying we should be having sex at least 2-3 times a week but we don’t. We NEVER have sex. My tummy is too big for him to be on top but when I was on top or doing doggy, there was a certain spot inside that never got enough lube and so sex was painful and we stopped doing it.

Has anyone got any tips for comfortable sex whilst pregnant?

EDIT- We used about half a bottle of lube each time but there was still a spot that would hurt