Hi. Thanks for asking in Healthcare Magic. Ortho Evra is a transdermal patch containing more amount of estrogen than the regular contraceptive pills, increasing the risk of estrogen related side effects. Such side effect depends upon the amount of estrogen absorbed from the patch and it varies in each individual. In fact an FDA advisory warns of a potential risk of increased thromboembolism in those with higher absorption rate. If your inability to stand for a long time is due to severe calf pain, you should rule out deep vein thrombosis, although such a risk rarely occurs within 2 days. Back pain may also be due to other causes. Higher estrogen levels often results in nausea. Probably, your rate of absorption of hormones from the patch is high. Transdermal patches are much more convenient than the OCP, which needs to be taken at the same time daily, posing a problem for young girls like you and may be that s why Ortho Evra has been prescribed for you. But since you are having severe back pain, nausea and inability to sit or stand, you should consult your treating Dr. to find out if it is safe to continue Ortho Evra. I hope this is useful to you.