Can I get pregnant on the first day off my period?

I have been on regular birth control (pill) for the last year, and have always used condoms in conjunction with the pill. Two weeks ago I had my period and saw my boyfriend on that weekend. This was the second to last and last day of my placebo pill, and the first day back on the actual birth control. We both wanted to know what it was like to have without a condom and ended up not pulling out. I know that ovulation is supposed to occur two weeks before the next period, so I should be safe (and I ended up taking plan B 36 hours after the because I got very nervous), but is there any danger of getting pregnant if unprotected is had at the very end of a period and immediately after it has finished?