I know that, if I hadn't heard that about my pill I wouldn't be so concerned... I do not take it every time I have sex and do not plan to because I know it is really bad for you. Probably I will not take it and pray that I am not pregnant and never have unprotective sex again. My question was if it was really that bad if I took it this time, since it would be the second time in my life I have ever taken.
You're not supposed to take plan b when you're already taking the pill as directed. You're already getting dosed with fake hormones from being on the pill and taking the plan b increases that dose to far higher levels, which leads to side effects ranging from just annoying (like spotting or heavy bleeding or missing your period all together for a month or 2) to deadly (like pulmonary embolism or DVT). It's not recommended by any doctor who knows what they are talking about.
The pill has been used for over 50+ years as a method for women to not have to use condoms. And there are tons and tons of women who rely only on the pill for birth control and never get pregnant. The failure rate from birth control when taken correctly is very low and not reason enough to take plan b on top of it.
Using condoms while on the pill is always a good idea if you want additional protection against pregnancy but it is not required. If you can't trust the pill plus a condom to be protective enough to prevent pregnancy then you're going to have to stop having sex because taking plan b every time you have sex on top of your regular birth control pill is not advised and should be avoided by anyone who values their health.