Why am I not getting a period?

I’ve been on BC for 10 years. From the pill, patch & back to the pill. I recently switched from lo loestrin fe to larin fe, & I had my period in October like normal, November was lighter than usual, & I’m supposed to be starting this week and haven’t yet and I probably won’t. When I was on loestrin I didn’t get a period at all for the 10/11 months I was on it & 3 months ago when I switched BC brands I got a Pap smear done and I have a small polyp on my cervix that came back non cancerous. I haven’t had sex since November 25. Unless I’m 2 months pregnant and don’t know it then idk what to do or why I’m not getting a period anymore. Thoughts?