When body first come in contact with sperm...

Christy
Hello, very new here and we just seriously started TTC about a month ago.  This is the first time in my life allowing ejulation in me and the days (1-2) following some BD almost make me feel nauseous, like a bit off, and with this bubbly feeling in my stomach, or maybe that's my uterus?  Is there such a thing that my body is rejecting or questioning what the sperm is doing in there? 
Anyone else felt this "different" or "off" feeling when the first times TTC?  
Again, we really just started and maybe this feeling will go away soon? Thank you!