Constipation or? Help!

Sammy

I'm 23+3 and I've been sitting on the toilet for the last 20 minutes trying too poop. I went to the toilet because I was getting really bad cramps (feeling like I had too poop cramps). I've managed to poop a little but sorry TMI it comes out as little rock like form. I'm still having pretty bad cramps. Is this normal? constipation or should I be concerned?