How Long Will The Pill Be Effective After Having An Unprotected Sex?

I went on continuous birth control (combined pill) around 4-5 months ago instead of taking the regular 21 day off 7 day style. I still have breakthrough bleeding every month during when my period is supposed to be, but I just continue taking the pill and it eventually goes away. But this last month, I had a period for 3 weeks. I called my gynecologist and she said to stop taking the pills for 2 days and then get back on them and stay on them. I stopped the pills for 2 days and had heavier bleeding. I started the pills back up and have been on them since. I asked her how long I had to use a second type of protection. She said that they tell everyone 1 month, but that most doctors say 2 weeks. She said to do a month because my body was all messed up and she didnt know where I was at in my cycle. The thing is I am going to Mexico this weekend and next week and was looking forward to unprotected sex with my boyfriend.

So, I only didn't take the pills 2 days and that was just to have a real period. I have been back on the pill for 11 days and will be back on it 14 by the time I have unprotected sex. All the research I did stated I am safe after 7 days of taking the pill and shouldn't worry, but I wanted to know if that was true and why only 7 days. What if I had ovulated? Thank you so much for your help!