I feel like im pregnant again?

Ok on march 19 i had my period& it ended on dha 24th. On the 26th of march me&my boyfriend had sex i was ovulating on the 26th. He came in me&on the 28th we had sex that morning& again he came in me. An when we woke up got str8 we had sex again&he came again and tht was the last time. But lately on today i felt like i had to throw up. But nun came up. My period was suppose to be dwn on the 2nd of dis month no period and it nevers runs late. Whats going on?