Vaginal Ultrasound in 4-5w?

So I just found out that I'm pregnant and been having this cramps and kinda gas sharp pain on my thigh and leg and twitching like had to seat down , went to the er cos I got scared and the doc said I'm pregnant cos they did both blood n ursine again and they did the vaginal ultrasound and couldn't see the embryo , that it's either not on the right spot, (ectopic ) or too early! I'm just nervous never been pregnant before been trying for a year , so I dunno what to think.

1) is it normal for cramping and twitching on the left side mostly the thigh and leg?

2) is it normal that u can't locate the pregnancy at that time?

3)Guys am I overthinking?