I'm having lower abdominal pain again (I went to the ER 2 weeks ago for severe lower abdominal pain. Pinching/stabbing…

I'm having lower abdominal pain again (I went to the ER 2 weeks ago for severe lower abdominal pain. Pinching/stabbing feeling) it's a punching/stabbing feeling, same as last time. I've been resting all day so I haven't over worked myself. I went to the bathroom and only went pee, when I wiped the toilet paper had a light light pink color on it, I've been having light discharge as well. I called the ER and they don't even seem concerned, the nurse told me that when the baby moves sometimes it can cause bleeding?? The nurse told me it can be ligament pain, but I'm more concerned about the pink color on the toilet paper! I'm nervous because I've never had pink color on my toilet paper before. I didn't see any blood or pink in my urine or underwear just on the toilet paper. I'm 18 weeks today and I don't know what to do! I don't know if I should go into the ER and get checkout out or just wait!