Big hugs my love.... My first thought was is the pregnancy a molar pregnancy? Did they discuss that with you?
Because your levels dropped and then rose again that is puzzling - and wouldn't be the usual course of events for an ectopic pregnancy. However with molar pregnancies this can happen... It can also happen when there is some pregnancy still attatched to the uterine wall - the placental tissue continues to develop and thus the rise in HCG...

Sending you my love and support...