Look, some people are saying it's about health, others about safety and myself about costs.
REDUCING THE RISK OF PREGNANCY
Oral Contraceptive Pill: 99.9%
Condoms: 95%
Morning-After Pill: ??
I'm not going into other contraceptives, but they're generally all 99.9% (minus condoms, of course)
HEALTH WISE (best to worst)
Condoms
OCP
MAP
COST WISE
Condoms
OCP (per 12 months... $60?)
MAP (one-off use... $30?)
To me, condoms and the pill aren't used for the same purpose.
One safeguards against pregnancy (pill), the other STIs (condoms).
If you want to protect yourself/your partner against both, then use both.
But it's no use saying that you wouldn't use the MAP because of health reasons if you're using both condoms and the OCP for double protection; because you're still pumping your body with hormones anyway so that argument is void.
Besides, if you were already on the OCP you wouldn't have to worry about the MAP.
Condoms are an accessory (when it comes to pregnancy).
Let's do some math.
Say you have sex 3 times a week and condoms are 50c each. That's $1.50 per week, for 52 weeks = $78.00
$78 + $60 (for pill) = $138 annually
Compared to $78 + $30 (one-off MAP) = $108
Both pills reduce your chance of pregnancy.
One is more cost-effective but not as 'healthy'.