Retain rights residence card

[Ialbuzi999]

Hi,
Non eea national was married with eea national over 3 years. Divorced and have 5 year retain rights residence card. When we seperated and started divorce process i met person who has helped me deal with stress caused through the divorce and started dating ,after divorce i was pregnant from new boy friend who is british citizen and now we want get married .plus me and my ex husband we were working since livinig in uk never claimed any benefits and are full time employed but my questions are:
1. I m going to my country for two weeks with my baby and my partner just want know what kind of questions i might get when i enter back to uk,as i am holding retain right card which i got after divorce ,but my british partner and baby will be with me any experiance ?
2.we want register martiage in uk and have an appoitment for that but not sure how it is going to effect on my residence card