First time on the pill I need help!

I went out of town for an emergency and missed Sunday & mondays pills.

Got back Tuesday and doubled up. (Monday & Tuesday) a friend told me to throw out the Sunday pill so I did.

I’m not sure if that was right but when can I have unprotected sex with my SO again??

This is my 4th month in it any never missed a pill so I’m not sure what to do!