It took my cat 50 minutes today to poop

I don't know if that's normal. It's completely new to me.

This is only the first day. I'm not sure if calling the vet is worth it though. It's probably constipation? But i'm not sure.

This is very abnormal.  I would get her to the vet to make sure she's not impacted and to rule out a blockage.

Update!

Vet said to feed cat tuna with a spoon of water (stirr 'em all together, Of coarse) and see if anything changes for the night. (If nothing changes, Go back to vet. If there's a developmen)

I went to do what vet said. Fed the cat tuna for the night with water.

Next day, Cat poops normally. No signs of struggles. Just that poop is a little liquidy and brighter than normal. And really smelly. I call vet and give him updates. He tells me to continue with the tuna and the water. Make sure to change it's water bowl twice a day and don't let him outside of the house and to call vet tomorrow for updates. I say "okay" and hang up.

Next day, Cat poops normally. No signs of struggles. Poop is less smelly than the other day. It's darker than last time. I call vet and vet says "we're cool. Cat's not dying. It's all good. Just keep it up till everything's normal. And don't hesitate to come if worried. Better safe than sorry." then vet hung up.

You want to continue feeding her regular food as tuna by itself doesn't have all the vitamins and nutrients your kitty needs.  Can you get or make pumpkin puree (canned) or squash puree?  If you add a little bit to canned food, it will help keep poops normal and make them softer and easier to pass.

Glad you are keeping in contact with the Vet.. It is very important to have a good relationship with them, and not to hesitate to take your kitty in, if things concern you!

Try adding some water to the wet food. Not to the dry because it gets moldy very fast.

Or, as stephainetx has stated, get a can of plain pumpkin in the baking section of the grocery store. Make sure it is plain pumpkin, without anything added..

Mix a bit of it with her food.

Or even baby squash, with out any additives...pure squash; that can be added to her food....