welcome to HCM,
since you got your periods at the completion of the second pack of the pills, it means you were not pregnant till then and the pills have started acting properly on your body.
secondly you have missed 2 pills in the third week of this pack of pills and had an unprotected intercourse
. ovulation occurs in the third week, so there are chances that you might have conceived .
plus taking a missed pill on the same day or the other day with in 24 hrs may help , but have missed the pills for quite long, so the protection may not be complete .
at home do a urine pregnancy
test before visiting the doctor.