Constant Period like pains

Hello I’m 39+3 days pregnant with my first baby, I’ve been having period pains for the past week or 2, it’s constantly there, I have passed my plug a few times but haven’t seen any more in 3 days just wondering if it’s normal? As it’s in my lower abdomen and a long my pubic line, baby’s movements are fine and just as strong just don’t understand the pain part, if anyone has had this or can explain to me why I’m feeling like this that would be great!