I'm scared

Hi to everyone, I'm 19 and Lutheran. Today I picked up my first birth control prescription and I'm scared. I'm scared because I have heard since I was young that using birth control is sinful.

I went to Catholic school before I went to a public high school and state college. I was told constantly that women who use birth control are sinful because they are preventing "the gifts of the Lord" or children.

Before I became Lutheran, I went to another Protestant denomination's services and nothing about birth control ever came up.

I am very confused about being a Christian and taking birth control. I lead my college's Bible study and my two advisors have told me that things like birth control are sinful, among other things that I can understand such as adultery.

However, I am going on birth control because for 5+ years my periods have been painful enough to leave me in tears and bedridden for over a week. Last year, I was diagnosed with PCOS and a few times over the past year I have missed classes and events with different organizations I am in such as CRU (Campus Crusade for Christ) because of the pain I have experienced.

I am not trying to prevent my ability to have children. I want to have children in the future, but I'm still in college, I don't have a boyfriend, and I am still trying to learn how to trust in God.

I simply want to feel better. I have been praying, but I am confused and worried.

Am I being sinful? Advice?