His Cum

Okay... this feels odd too ask... So my husband cums in me and when he's done and pulls out there is frequently more that flows out of him like it was trapped or something. After he ejaculates we relax and give it a moment and he tries to get as much in me as possible since we both want a baby desperately... None the less we are frequently dealing with this issue. Position, time left in me, angle etc don't seem to make a difference.

Has this happened to anyone? Is this common? How do we get as much inside me as possible? What's your advice?