IUS/IUD

Lauren
Hi ladies,
I have an appointment to get either the jaydess/skyla or mirena IUD/S fitted on Tuesday however I'm having second thoughts. 
Currently on the mini pill and it's made my periods unbearably irregular which is why I'm changing methods. 
Has anyone had any experience on these and how long did you bleed for after fitting? That's my main concern as holiday is next month and chances are it won't be enough blood for a tampon but they'll be too much to go without😁 any advice would be greatly received - oh and effect on your sex drive/libido? (I haven't had any kids either) Thanks xx