Can I switch formulas?

They had me on Similac Pro-advance at the hospital, but once we got home WIC didn't cover that so they switched her to similac advance. She's 2 weeks old today, and has been super gassy, fussy, and spits up a lot since we've been on advance. Is it safe to switch her to Similac Sensitive? Is it okay to just switch? Picture of her because I just like showing off her preciousness. 💗