Enemas safe during first trimester!?!?

Jessica
I am severely constipated and have a BM the  size of a pop can down near my rectum that won't come out (sorry for the tmi) I have tried ducosate sodium, Metamucil, water and coffee and it's not helping.. Was thinking of trying glycerin suppository today and if it didn't work was going to try enema... Please tell me it's safe?