I'm between 14 and 18 weeks pregnant and me and my boyfriend had sex last night (it wasn't rouh or anything) and after I noticed I was bleeding a little is this normal ?

I have had 2 kids and a lot of times after sex I bled a little. Haven't you ever heard of woman that flow through there whole pregnancy? I happens a lot. It's normal, if you are really concerned call your OBGYN.

This site may help.
Bleeding During Pregnancy : American Pregnancy Association