Over flow incontinence 18 weeks

Ladies I'm having trouble every time I go toliet for a pee. I'll empty my bladder and think I'm done then alot more (sorry for the gross word) dribbles out and then I think I'm done and the same happens again I can't stop it either!? Then after I'm "done" I leak a little in my undies. I'm almost 18 weeks, I have leaked in the past before being pregnant but nothing like this? Has anyone else experienced this!!!??