I would defiantly say the steroid could have an effect on your body. I was on birth control the first 5 weeks of my pregnancy and it did not hurt the baby at all, it happens to a lot of people. I would just be extra careful if you decide not to take it! cheaper then a Dr. appointment would be to take a pregnancy test, if I were you buy more then one cause you will probably not believe your first one. Take it during you first morning pee because your HCG levels will be at the highest. If it is negative wait a week and take it again, if its still not showing up you are probably not pregnancy.
Taking medications can cause delayed periods. Take a home pregnancy test; it should be accurate a week after your period is due. If it is negative you are not pregnant. However if you are having that pain where your ovary is AND having discharge (clear, white discharge when you use the restroom) it could be that you've ovulating and ovulating late (could also be delayed by the steroid).
How are you feeling? One thing that I know a lot of women feel early in the pregnancy before even find out is very noticible fatigue, and u should take a pregnancy test. And if that comes out negative, take it again in a week to be sure, other than that it could be the steroids that is messing u up. I know how it is to not have insurance, I didn't have mine until I was 5 months pregnant lol.