You may be out by about a week. Assuming you ovulated around the 25th April, you could get a faint BFP by 3 May. It would be about 8-9dpo. That would make you about 6 weeks pregnant. Sometimes that's too early to see anything in the uterus. Many people wait until 7wks before having a dating scan.

You can still have normal hcg and have an ectopic. Mine was within normal range but I had other indicators, like extreme pain.