when should I begin to worry - please help!

I’ve been wondering this for a while. so I am on the pill and I am worried that when I was prescribed my hormone dosage, I was lighter, and now I worry that my dosage is not enough to work for me. Is that a common occurrence? I am not much heavier... like MAYBE only ten pounds. I just worry that my dosage is not enough to work on me because I’ve gained weight even though my doctor prescribed me the pills.

Also, if I miss my withdrawal bleed, should I be worried I’m pregnant? I take my pills perfectly. I took my second sugar pill today at 8 PM (it’s 11 PM now) and still no bleed. If I miss it, should I be worried I’m pregnant? Or not? When should I worry and test?