Birth control pills are very safe for women who do not smoke, and women who do not have a family history of blood clotting disorders.

BC pills put your ovaries at REST, the hormones in the pill are responsible for doing this.

The hormones create a cycle for you, and then you can have a period, if you want one.

Don't worry yourself too much. I went on the Pill when I was young to get my periods regular and I'm fine 7 years later
The only thing you might notice are mood swings (think killer PMS) and your skin will probably clear up. There may be other things, like realy sensitive breasts or breast swelling, when you first start but those sort of things went away for me after the second month.
Some women have other problems, like decreased sex-drive, because the Pill basicaly tricks your body into thinking it's pregnant. Your period comes when you take sugar pills, the hormones in the active Pills wears off, and you bleed because your body no longer thinks it's pregnant.
(At least that's my understanding of the basics, if I'm wrong please let me know
If your Dr. put you on the pill your it's probable fine for you to take it.

If you have realy heavy, irregular periods though, progestorone cream may be better for you. It realy helped me out, lightened my periods from 10 days of heavy bleeding to 4 days of normal flow and regulated my cycle too. Most Dr.s don't know about it because it's a bit of an "alternative" medicine (the cream can't be patented so drug companies can't make a fortune out of a one-of-a-kind-cutting-edge-formula and therfore don't push it's use). Worth a try though if you're just after regulation not contraception.

Well I think I've rambled on long enough, hope some of this helped