If you need to take medication that has to be taken during the daylight hours you can't fast because you have to look after your health.
When you get your period you get a dispensation from fasting but you're meant to amke it up before the next Ramadan or some schools say you can pay the cost of feeding a starving person for each day you miss.
The reason that the pill is relevant to me and Ramadan is that I skip the sugar pills for 3 months and only have a period every 4th month. This Ramadan I won't have my period so excluding any unexpected sickness I'll be able to fast every day instead of missing 6 days when AF arrives.