I had a pill abortion 2/3 days ago, tomorrow I have to go somewhere important and would prefer to use a tampon, what's the chance of me getting an inf?

Mini pad works! After an abortion the cervix is now wide open and very susceptible to infection from items placed in the vagina. A tampon will remain in place for a few hours and can serve as a nidus and conduit of continuing infection. A mini pad is your best option.