15 month old sleep issues! Help!

So my almost 15 month old was never an amazing sleeper but we sleep trained and she was doing 6pm-6am pretty regularly for a long time. Would sometimes wake up but put herself back to sleep.

But for 2 weeks now she wakes up EVERY NIGHT at around 1-2am and cries and screams until like 3:30-4am. I usually go in after a while to check diaper, rock her, giver her warm milk but she will continue crying when I put her back down.

I just don’t know what the issue could be. She just started daycare and was sick but is better now so idk if its all linked. She also just pierced 4 molars.

Seems like a lot is going on at the same time for her so its hard to know what is causing this.

Im tired and 6 months pregnant and just ready to sleep LOL

Anyone has been through this