Please help!!!

5w3d went for a wee earlier the tiniest faintest bit of blood on the tissue went to A&E had a transvaginal ultrasound and the couldn’t see anything apart from what they thought could possibly be the sac but said it’s too early to tell, has anyone else had this bleeding? Or even anyone else went for US at 5w3d and the couldn’t see anything and it went on to be a healthy pregnancy?? Doctors just phoned to say my HCG is at 4500, Can someone give me some advice I’m freaking out also I’ve had a previous ectopic pregnancy.. 😓😓😓