Can the IUD be felt during sex? Does it cause weight gain?

I’m considering getting an IUD after not being on birth control for over a year. I just had a few questions for anyone who has experience using an IUD. Can you feel it during your day to day life- is it uncomfortable? Can it be felt during sex? I’m nervous that if I’m having rougher sex it might hurt me or get pushed into something. And did anyone notice a considerable weight gain after starting it? Any other comments or information would be greatly appreciated!!