Tattoo while on period?

My period came a week earlier than it was supposed to and it really, really hurts. Grant you, this is day 1 and it usually dies down. However, I made my very first tattoo appointment (a tattoo in memory of my grandmother who died almost a month ago) for this Saturday. So 4 days into AF. Ovia is saying it'll be done on Sunday. It is possible I might end sooner, because I have had periods that have lasted only 3-4 days, and it's a very light period thus far, hardly bleeding (just the cramps that are god awful). But just Incase I am on AF, is it okay to get a tattoo? My sister said you should never get a tattoo while on your period. Will it hurt more (it'll be on the back of my shoulder)? Can I take Midol/Advil or will that make the tattoo bleed more? Any help would be super appreciated.