welcome to healthcaremagic,
since you had your periods recently and had not had any intercourse there is hardly any chance of pregnancy
.still if you have any doubt you can always go for an easy home done pregnancy test to confirm yourself.
the mistake you have done is taking two pills in reverse order.not a mistake at all. there is no problem if you take few pills in reverse. the composition of the 21 pills in the pack is the same.
kindly show to a physician for your symptoms or take some symptomatic treatment.
i hope you will get well soon .