No, you'll be fine. A lot of people skip the week by choice because all you do is listen to people talk about the uni and learn to get around. If you're one of the sociable ones, you might even make a few friends or gain acquaintances.
Because I'm such a socially anxious weirdo I went to most of the things at mine though I missed a really important talk yesterday because thanks to two of my oldest "friends" who I just don't want to know anymore, I had a panic attack and started crying whilst on the phone to my sister - WHO, btw, had no idea I was having the panic attack - because I was just so pissed off at the whole situation with my friends and I was overwhelmed with starting uni and overwhelmed with not having a job and no loan to fall back on. My sister literally shouted at me for getting so emotional. Thank god for tough love. This wasn't in uni, btw, so thankfully no one will know me as "the girl who gets pissed off and cries because she was never taught to appropriately deal with emotions!" ANYWAY! If you're anything like me then you're lucky to have missed this sort of drama, if you're nothing like me, and I don't know how you would know this considering you know nothing about me other than the fact that I may spontaneously burst into tears when I'm having a panic attack whilst being made to confront rageful anger, then lucky you! Oh yeah, I also skipped some welcoming drinks gathering thing or whatever which happened today - I went in for a talk on my course then walked out straight after. Induction week is just that - you choose to go in if you want to and choose to walk out when you want to, it's not too important. Even parents can go which I thought was really weird.
Soooooo I forgot what I was writing. Oh yes, don't worry. All that matters is you enrol and if your course director said you can enrol at another time, then you're still good to go! Induction week is literally just an introduction to the facilities, services, course and things like that. It's pretty boring and slightly useless. When you do go in and make friends just ask them about what happened and they'll fill you in. Don't worry too much.