brown discharge after sex? 18w2d

Ashley
So our sex life has changed since the pregnancy...first trimester I could barely touch myself let alone let him even come close to me without throwing up! THANK GOODNESS I'm over that! So we have been making up for lost time since I finally am able to keep food down. The last time we did the deed there was quite a bit of brown discharge after we finished. It startled both of us but there was no red blood or cramping...is this normal?? Calling midwife tomorrow to be sure!! 
Anyone else experience this? I am 18 weeks and 2 days with my second!