Where is the sexual interest?

Last week my boyfriend and I had sex. Our method of protection failed. Afterwards, we sort of panicked and discussed whether or not I should take emergency contraceptive. We talked for less than 2 minutes and in a frantic state, my boyfriend told me he regretted having sex with me. We've talked about our future and having children, but we've never had THIS issue or discussion before, so for this to be his initial response really upset me. I walked away, took a huge breather, let it go and nothing more came of it. The other night, in the middle of his very relaxing three day weekend, I offered him oral sex. He declined saying he was tired and going to bed, but then proceeded to play an additional two hours of video games. I told him to let me know when and I'd be ready. Well, I got home from work tonight and talked about giving his bj rain check. He declined again saying he decided to masturbate instead. The biggest kicker is that I thought it was all in my head until I started documenting our sex a few weeks ago. Now, this may sound strange but I wanted to ensure that it wasn't me assuming the worst. So, I wrote down each time we had sex, who initiated sex and whether the other party declined. Over the past 3 weeks, I initiated sex 12 times, he initiated sex twice. We only had sex three times, two of those times were when he initiated it. I don't know what to think and I don't understand the lack of sexual interest. We're in our mid twenties and our home and work lives haven't changed. There are more examples and instances but these are the most recent.