On so many meds

I am currently TTC since August. Got my period back in September and now the October one is 4 days late. I don't have many symptoms other than fatigue, sensitivity to smell and constipation. I have also been very moody and can't decide if it's because I'm prego or PMSing. I also was diagnosed with pneumonia almost 2 weeks ago and have been on antibiotics since then and got several chest x-rays and even a ct scan of the chest. Could the antibiotics be preventing me from getting my period? Or what if I'm pregnant? Will any of this have harmed the fetus? I am so confused and need some womenly opinions and advice here. Too nervous to test now :/