Pregnant after an ectopic

I’m pregnant again for the first time since my ectopic pregnancy a few years ago and I am stressed. I’m 4w3d. So not very far along at all. I’ve been having some cramping and dull pain off and on. I don’t know how to decipher between regular pregnancy aches and pains or another ectopic pregnancy. I’ve had my HCG levels checked. They’re low but did double like they’re supposed to. I was told I’ll come in for an ultrasound/confirmation of pregnancy at 6w2d. I’m not having any bleeding at all not even spotting. Everyone I’ve told that I’m pregnant to keeps telling me I should go into the ER and make them do an ultrasound to make sure the pregnancy is in my uterus this time. But I don’t want to cry wolf. I also don’t want to risk going into the ER, having them decide to do one only to tell me they don’t see anything yet because I’m only 4 weeks 3 days. I guess I just really need some advice or opinions of anyone who’s gone through this before too. Please.