Missed period. Can you help?

I took two ipills in the months of August and September. Although my periods came heavy and quicker but they were there. I was going through my cycle on around 5th October and then on the 3rd of November. I don’t remember the exact dates they started. But these dates are probably of the 3rd or 4th day. This month I’m yet to have my period. I thought it would start around the 26th or 27th but all that happened on those two days was a little spotting. On 28th I had unprotected intercourse thinking it would be safe because my period was about to start but no ejaculation was done inside and I did not have an Ipill. I used to smoke as well but quit smoking on the 20th November and started using a nicotine patch which gave me nausea at first. I had a relapse on the 28th, 29th and 30th. But I'm back on the patch again. I'm confused as to why I missed my period because I did not have intercourse between my last period and 28th November. Can you help?