Fetal doppler

So I caved and got the Sonoline B fetal doppler. I watched a video on how to do it which said to push a little when doing it while listening for the heartbeat. I was 7 weeks and didn’t hear a heart beat but started to feel like cramps or dull uterus pain in the pelvic region so I just stopped doing it because it made me nervous. I had been doing this maybe for 5-7 min before I stopped.

I think I am over thinking it but I feel as though I haven’t been nauseous since that happened so I am nervous I over heated the baby and lost it.

I have my first ultrasaound tomorrow so I will know for sure, but has anyone else experienced using the Sonoline B Doppler that caused baby loss?

Thanks!