Lower back pain at 8w3d

As the title says, I’m 8 weeks 3 days. I have a subchorionic hemorrhage.

On Thursday I went to the OB and saw a little baby with a heartbeat. 171 BPM. Also saw a 2x2x2cm SCH.

Today, I’m having some lower back pain. Came out of nowhere and was pretty intense. It’s since calmed down a bit, but it’s still there and I’m very scared. I’m also cramping a bit. I called my OB and they said if I’m really worried I should see a doctor at urgent care or the ER, but I’m wondering if I should.

I’m quite worried but also thinking I’m overthinking this. Please help!