Birth Control options. Avoid pregnancy?

We are a newly married couple. And we want to understand birth control options as we are not ready to have kids yet. Looking up online on the matter suggests that birth control pills are effective but have side effects on women's health and may effect health of future kids as well. What birth control practices should we follow (we are already aware and using condoms but even they are not 100% effective)? To give a background about myself, I have a healthy body and do a lot of walking to keep my weight under control. However, I gain weight much faster than usual people if diet is not controlled properly. My periods are accompanied with pain in abdomen for 2-3 days every month. They are usually delayed by a couple of days every month as well. Are birth control pills advised for me? Are there any alternative natural ways to avoid pregnancy?