stomach pain

okay so I am 5 weeks and 3 days I believe but I've been having these really bad pains in my stomach and I called my doctor and the nurse called me and told me that I shouldn't really be having pain this early in my pregnancy and so she told me to take some Tylenol and I did and it wore off in like 20-30 minutes so she told me to come in the hour but my dad and we were talking and he said that he would take me in if I'm still not doing good tomorrow or if I wake up in the middle of the night and I'm still hurting but I still am and so I'm wondering if this is just a normal thing like my husband said that we might be having twins while he's been having dreams that we're going to be having twins this pregnancy and so I don't know if we are and my uterus is just expanding and it just making my stomach hurt or if there's something actually going wrong that I should go to the ER so I just want to see what you guys think I should do just wait it out or go to the ER