Hi. I'm 22. I missed two pills in the first week of taking Mercilon. I started taking Mercilon in Nov this year (last month). After my first 7 day break I took it on Monday - Wednesday then forgot on Thursday to Friday. I then remembered on Saturday afternoon and took Fridays pill Sat pm then Saturdays pill at my usual time of 10 pm.(So Thursdays pill is left in the packet) I had sex on Thursday pm and Saturday am. Too late to take Plan B now. Should I be worried?