IBS ?

for like the past 4 days my stomach has been acting hella weird i’m on nexplanon so weird ass 8 day period just ended and for the last 4 days i’d say my stomach has been acting so weird !! my stomach would cramp up , id get a little nausea and then i’d have to rush to the bathroom and it’d be diahrrea (tmi) the stomach cramps would go away after i finish then maybe 30min-1hr later i’d have to go again ???? usually i’m ALWAYS on the constipated side (so sorry for the tmi) i’m 21 y/o and i just had my son about 4 months ago idk if that makes a difference my diet is awful , i always get hot flashes and for these past few days when i did have to rush to the bathroom i’d only go 2-3 times and then my poor stomach will be bubbling !! like tonight !! now i’m just sitting here hungry but scared that when i eat my stomach is gonna hate me again and i just hate the feeling of when my stomach hurts .. not sure what’s triggering it please help