Weird pulling sensation down there - 4th week pregnancy

Does anyone else feel weird pulling sensation down there- not in abdomen today, but V area, like periods is coming .

Today is my 4 week 6 days.

Last Hcg drawn was on 4 week 2 days - 548

Previous Hcg was on 4 week - 302

It was a 81% increase.

I have my ultrasound scheduled on Friday.

I am also tracking my body temperature by Apple Watch which is elevated from the base line.

Still I am really worried about the cramps & pulling sensation. Is it normal ?

Someone please guide me . It’s making it crazy .