Alamak, this is quite common actually, a few of my mum friends mentioned the same thing masa 7 bulan pregnant! Your uterus is getting really swollen and sensitive, so sometimes after intimacy boleh feel like ada pressure or heaviness down there, which is totally normal kalau no bleeding or cramping. But just to be safe, best check with your gynae on your next visit or call the clinic, they can do a quick check and set your mind at ease, and maybe give you some tips for staying comfortable during this stage.