Anyone else? Maybe tmi

I'm 7 weeks and 2 days and got to see my baby with a heartbeat Monday then yesterday I first had stabbing pains up my vagina and then once that went away I had and still have heavy pressure/pain down there as if I have a full bladder from holding my urine all day even though I'm constantly going. And I had horrible pain in my left lower back. I called the Dr's office and the nurse checked my baby again which was fine and said I only had a trace or a possible uti but they gave me antibiotics anyways.. has anyone else experienced something like this? I thought I had a uti with my last pregnancy but ended up have a miscarriage so now I'm worried