What has made me infertile? Am I infertile?

We have been trying to have a baby for the last year and a half. And it hasn't worked for us. Let me give you a little background of us.
I am 20, he is 25. We just recently got married, however, we have been together almost two years.
Before we were together, he used to drink a lot! (I am only saying this because I am not sure if this has an impact on fertility or sperm count)
About three years ago I took the depo shot. (I only took it once) For a year after that one shot my periods were not normal. The past two years have calmed down a lot though, and have became pretty consistent and regular. Until the past six months. I had a period six months ago. Skipped two months. Had one. skipped a month and had another one. That is where I am at now.
My husband and I have never used a condom.
Six months ago I went to the dr and was told that I had BV (bacterial vaginosis) however, I was also told that this would not cause me to become infertile. I took the meds for the vaginosis, and that is when my periods went crazy.
We have went to the dr, and it would be a lot of money for us to have the both of us tested. (neither of us have kids)
This is my last straw before I go an spend a ton of money trying to have a baby.
Please someone help us!!
Any advice you could give would be so appreciated!