I'd call the admissions office, or better yet, use email if you have the email of your admissions counselor. It may have gotten mixed up in the mail somewhere. If it's not there then there's not much you can do except to call your HS and have them resend your transcripts. You will still be accepted, and if the administration is anything like some State Colleges, they'll admit you and won't ask for your transcripts till you graduate, at which point they'll notice that your academic file is not complete

! Still, it's a good idea to get that in with some kind of confirmation as soon as possible.
Kuan
PS: It's normally a good idea to request that your transcripts be sent registered mail. You might want to consider that the next time you have transcripts sent out.