Postive Test too early

Aristea

So I had a miscarriage in October at 8 weeks and we started trying again in December after my levels were back to normal. I got a positive pregnancy this cycle at 10 dpo. Tested again yesterday and again had a postive at 13 dpo. I called my doctor to make an appointment and they sounded really concerned that I had a positive already because my period isn’t due until Wednesday. They want me to come in to have an ultrasound and blood test done to confirm dates and ensure I’m pregnant. Should I be concerned? Has this happened to anyone else?