I wouldn't worry to much, what will be will be, and vomiting and small tears aren't that bad anyway. I spewed once while I was getting out of the bath to leave the hospital, and I tore and didn't realise it til they said I'd have to get out of the bath super quick cos they had to stitch me up (I was losing a bit of blood).
Did you say you were going to a birth centre? Do they do waterbirths? I wonder if the water was why I didn't realise I tore..?

All the best, and honestly don't worry about it, you don't worry about the spew and tears for long, especially once your gorgeous baby is in your arms