Some facts about birth control:
There are two common kinds of combination pills, monophasic and tri-cyclic. Monophasic pills give you the same dose of hormone regardless of time of month. Tri-cyclic pills change the dosage of hormone depending on the time of month. Combination pills consist of varying levels of synthetic estrogen and synthetic progesterone (progestin).
Another kind of birth control pill is the minipill. The minipill, while not commonly prescribed any more, contains only synthetic progesterone (progestin).
Other methods of hormonal birth control include the ring (Nuva-Ring), the patch (Ortho-Evra), the shot (Depo-Provera), and a specific IUD (Mirena). All of these methods use varying levels and kinds of hormone. For example, the ring is similar to a monophasic birth control pill, as is the patch. Depo-Provera consists only of progestin, and Mirena is an IUD coated in progestin.
Side effects from any method of hormonal birth control vary widely. Being responsible for one's sexual health means being aware of what the risks of birth control are, what possible side effects are, and pursuing another method if the side effects become too much. Yes, hormonal birth control changes your body chemistry--essentially it tricks your body into thinking it is pregnant so that it won't release an egg at ovulation--so you must be aware that there will be changes in how you feel. Some women are very sensitive to the additional hormones while some are not. There is no pill or method that works perfectly for everyone. You must be willing to talk honestly with your doctor in order to take responsibility for your sexual health, and if you cannot do so and cannot take responsibility, you shouldn't be having sex.
There are other methods that are non-hormonal--for example, barrier methods. Some of these are as effective as hormonal methods when used correctly. The diaphragm, the cervical cap, condoms, etc--all of these are possibilities when it comes to barrier methods, as is a good ol' Copper-T IUD. But again, these methods aren't for everyone: people with latex allergies should probably not use a diaphragm, some women have allergies to the spermicide that must be used in conjunction with a diaphragm, and in some women the Copper-T causes heavier periods and worsens menstrual cramps.
With every method there is the element of prevention of pregnancy, but there are also those side effects--good and bad. For instance, some tri-cyclic pills have been shown to reduce facial acne. Many women use hormonal birth control to regulate their cycle, lighten their flow, and reduce their menstrual cramps. There is also the possibility the flip side will occur--many pills cause weight gain, irritability, mood swings, and if you are a smoker hormonal birth control is not the wisest choice, as smoking on hormonal birth control increases your chance for blood clots.
As for myself, I have been on birth control since I was 17 and I am 23 now. I was on Ortho Tri-Cyclen for a long time but didn't like it because I didn't like taking a pill every day. Recently, I switched to the ring, and I love it. I don't have to take a pill, I don't have to get a period (because it's monophasic I can just skip the week off like one would with Seasonale or a continuous cycle of monophasic pills), and when I do get my period it lessens my flow and therefore my chance of horrendous menstrual cramps. Plus, I know it's there and I know it's working
There's no chance I'm going to mess it up by forgetting anything, which is the best part.
But as I said, everyone is different, and you should go to the doctor for an exam/consultation and have a long discussion about what, precisely, is the best method for you and your situation.