How do i convince my teacher to let me come to cl late?

I am on crutches because of my ankle and i need to go to the science building for cl in the middle of the day. I really am not that fast on my crutches, so I really need some extra time. I have to go to something (an elective) which is in a DIFFERENT building too. I can't really carry many things at once (duh) so I just can't bring my science stuff to that elective.. No one in my elective is in my science cl, so i can't make them carry my stuff to that building the science building. That means i need to go on my crutches from one building to another to the science building. IF someone isn't there on time, she makes them walk to the main office and get a slip (the office is in yet another building and on the whole opposite side of the campus. I don't want to walk on crutches to four different building... I will end up getting there about 30 minutes into cl! I emailed her asking if i could come in late, but she vetoed that idea... Is there anyway i can convince her to let me just come in like 10 minutes late?