my mind won't stop racing .... I'm so worried I had my baby 4weeks ago C-section and 2nights ago my…

my mind won't stop racing .... I'm so worried I had my baby 4weeks ago C-section and 2nights ago my fiancee and I had sex.. I'm not on anything as far as birth control until this coming Monday that I go see my gyno.he gave me some bloodpressure pills and said that the bc would interact... what are my chances of getting pregnant I don't want another baby yet I know I should have waited but I got caught up in the moment.... please need advice!!! I'm kinda cramping but IDK if I'm getting ready to start AF. fingers crossed that I do....