Period nightmare! GUYS: How would you react?

I was at my boyfriend's house yesterday but it was storming very badly so I had to spend the night unexpectedly. I'm on birth control and we're sexually active. He's 22 and I'm 17. It is my first month on birth control and I was a virgin 2 weeks ago. We both knew I was starting the second color of pills the next day, but I didn't expect my period to start in the middle of the night, and I didn't have any tampons with me and I didn't say anything to him about it. I woke up in the morning and it was a mess, I got blood on his white sheets, white carpet, and white bathroom rug. I feel sooooooo stupid. I managed to hide the mess from him long enough to get him to take me home, but as soon as he gets home he will see it. He dropped me off an hour ago and he only lives 30 min away but I haven't heard from him. GUYS: How do you think he will react?