You have already taken ECP and done all you can do right now to prevent pregnancy from happening. What you can do is just try to stay stress free and wait for your next period to come. You can also get pregnancy test kits to test around the time your next period is due.

Do note that ECP messes up the menstrual cycle and it'll be no surprise if your period comes earlier, later, or last for few weeks continuously. Give your body up to 3 months for the hormones to get back to norml

well wear protection and have more sex...its helps to calm you better.
 

Avoid having sex during fertile period. After that, feel free to have sex. You can also have fun without having penetrative sex, although not as awesome but it is a good stress reliever as well.

So far I haven't seen any limits on the amount of ECP that can be consumed a month but it is commonly acknowledged that ECP being for EMERGENCY use only, shouldn't be taken frequently. Yes, there are lots of other side effects. Some will experience it and some don't. Not everyone will have their menstrual cycle messed up. Each time you consume ECP, you may also experience different side effects. If you've read thru this thread, I've mentioned before that sometimes when I take ECP, there is no effect on my body or menstrual cycle at all. However, there are few times when I had continuous bleeding (up to 1 month bleeding). More common ones are having my period come early few days after taking ECP. Again, everyone body is different and the pills affect everyone differently. From my personal experience, I haven't experience vomiting, headache or dizziness before. It works most of the time so don't worry yourself too much. Stress is one of the biggest culprit in delaying menstruation.

For some reason, many people tend to think that period must come on the exact same day of each month to be stable. I don't know if you think that way too or you phrase your sentence wrongly. But I just wanna point out that every month does not have the exact same number of days and menstrual cycles can range anywhere between 25 days to 35 or 40 days. How you know whether the cycle is stable of not (and how you predict your next menstruation dates) is by calculating the number of days in your cycle. If your period came on the 5th this month, it does not mean that your period will come on the 5th next month.

Accident happen cham lo...hahaha. well then its best to stay away. Then the best is to practice your foreplays then. 

Well as munkeyflo have advised, there is no limit to how many you can take but then ECP can cause inconsistency in your period and it will take some time for your cycle to be back on track again. Do take note that ECP is purely hormonal tablets. The side effects that you see on the web is only lesser then a handful.

Calculate the number of days usually just +- 1-2 days if stable, shouldn't differ by the weeks. Get a period app on your smart phone to be more accurate and convenient to chart the cycle.
If you have a nicely chart menstrual cycle, spotting your ovulation dates (unsafe time) is much more easier. I'm not saying you must but just giving you more info.
http://divacup.com/educate-empower/tracking/
http://www.webmd.com/baby/charting-your-fertility-cycle