Sex during pregnancy

So today I was having sex with my husband and after we were done, I started to feel extremely nauseas and I wanted to throw up. I felt so weak and like I needed air. When I thought I was better, I stood up and went to pee, then I started to feel super weak again and felt like I was about to faint, I barely stood up and went to the couch to lay down. My husband brought me some water and flavored ice to calm down and it helped me. Is this normal? Should I worry next time I have sex with my husband? I’m 11 weeks with 4 days and this is my first baby.