I just started tri previfem. Previously I had been on junel fe for about 5 years. I am on my fourth day of my first pack of tri previfem. I took it the day after my placebo pills ran out of my last junel fe pack. I however didn't take any of those 7 placebo pills in the last week before starting tri previfem. my boyfriend and I had unprotected sex two nights ago. am I at risk for pregnancy?