Huge mum guilt!

I’m 23 weeks pregnant and also very emotional, exhausted and suffer with anxiety and major baby brain. My son is only 4 and I’ve take him into school this morning completely forgetting it’s non school uniform day and his wearing his uniform. I feel so bad for forgetting although he wasn’t too fussed about it but he was literally the only child in his uniform and I don’t want him getting made fun of, it was just the look on his face when he noticed everyone else and I just couldn’t help but get upset for him. when I got home I started crying. Has anyone else done this and is it normal to feel like this?