Natural constipation remedy?

Ugh ladies. Sorry for tmi in advance lol but I need help! My period is for sure on its way right now... I’ve had spotting and mild cramping, and it’ll likely be in full force by this evening or tomorrow morning at the latest.

The issue is I’m totally constipated. I know if I skip a bowel movement today I’m going to have an upset stomach tomorrow (that happens every time I skip a day!) and that’ll be on top of having my period cramps. I can’t let that happen it’s going to be awful :(

At the same time, the only things that really help me push along my bowel movements is really eating, and COFFEE. I already ate breakfast and lunch, and nothing. I’m afraid to drink coffee because it’ll exacerbate my cramps 😣😩

Help me poop guys! I’m scared I don’t want to be in pain tomorrow