keep feeling this almost pulse - like feeling in my stomach. like a heat wave but only in my stomach…

keep feeling this almost pulse - like feeling in my stomach. like a heat wave but only in my stomach and it rushes from top to bottom super fast (like a pulse). the best way I can describe it is like a hot flash but ONLY in my tummy. anyone else had these? my mom said maybe it's the sac separating from the walls of my uterus to prepare for birth but....I mean how many of us actually listen to our mothers XD hahaha