Baby at my belly button at 17weeks5days

Everything about this pregnancy confuses me... first off I have horrible pain and pressure that doctor cannot tell me what it is.. I am receiving progesterone injections weekly and I’m getting the weekly ultrasounds to check for shortening cervix.. everything looks great so far! (Thank God!)🙏🏽 (just can’t do anything about pain.. I can barely walk some days.. I’m dared baby could fall out especially since I previously had my water break at 18 weeks with my last pregnancy.. I worry.

Second, each time I get an ultrasound or hear heartbeat the baby is in a different spot... today with the dr. The baby’s heartbeat was found low a few inches below belly button .. (doctor said exactly where she expected)... once I went for the ultrasound (same day 30 minutes later) baby was right at the belly button.. directly under it.. I could feel it laying right there! (Tech said “wow baby’s laying really high!”) now I’m just confused! Lol

I asked if that means baby is big and she says not necessarily.. just means baby is all over the place and moving all around. I really didn’t think baby could be so far up at less that 18 weeks ..

I wish I knew more to put me at ease.

Do you guys think maybe baby could be big and causing me pain and pressure?? (Even though they never changed baby’s measurements or due date and never said baby measures big) anyone else feel baby at belly button at 17-18 weeks?