So even if you don't have the money, you may still be able to use the method you want. Many campus health centers offer low cost care to their students. At Cal Poly Pomona, for instance, office visits are free, and pharmacy items, both prescription and non-prescription, are very low cost. Shop around for non-prescription items such as condoms and spermicide. The price can vary significantly from place to place depending on how trendy the location is or how much they mark up their products above cost.
Cost can be a big factor.
Do a little research to make sure the method you choose is one you can afford and have access to.