So I'm almost 26 weeks (25.4) and was wondering, when did you really start to notice/track Braxton hicks?

To my knowledge I haven't even had any, and this app keeps asking if I've had any.

Now I am 5ft 0" and I'm 245lbs (238 prepregnancy) and I don't know if that may have anything to do with it but figured I'd add that.

Any concerns I should have? What exactly does it feel like? My friend recently had her baby and said it never hurt so no idea what to really really expect here :s :s