I second what the PP said about hiccups. I feel them below my belly button and sometimes down by my butt (!) which makes me pretty certain baby is head down
I have never been able to tell very well myself. My midwives tell by feeling my belly. If you’re trained, it’s super easy. One midwife at my practice, since retired, had a shockingly good success rate at telling boys from girls simply from feeling their bottoms!
Re: Baby position
https://www.spinningbabies.com/pregnancy-birth/baby-position/belly-mapping/