Odd problem!

Hello guys!

My pup is 7 months old and 100% toilet trained, she started her first season at the beginning of the month and has JUST stopped bleeding two days ago.

The problem I'm having is that for about 5 days, she's been peeing normally, but not pooing all day, and then around 4am she has a massive explosion as if she can't hold it, but it's not diarrhea! It's like she's holding it in all day dispite going outside, and then at night she's realising that she needs to go, and it's so sudden that there's no way of letting her out!

I have no idea what to do, has anyone experience anything like this before?!

I'm at my wits end, I thought I was done with picking up accidents haha!

Maybe a trip to the vet is in order. Have u tried feeding a bit. Earlier at night?