Hallow Elizabeth, If you are having your menses very irregular, after two weeks or so, the chances of your pregnancy are much less, since such irregularity is more likely to be associated without egg release. Moreover, from your history it appears that you had intercourse within few days after menses. At this phase of menstrual cycle, egg is not available for fertilisation. Moreover, you have taken plan B pill within 72 hours of both the condom failure incidences. You have covered yourself to protect from pregnancy. Still, you may undergo pregnancy test on overnight first morning urine sample after three weeks more if you do not get your periods by that time. I would advise you to consult your Gynaecologist for your menstrual irregularities. Such abnormalities in menstruation can be corrected with simpler treatments if treated early. At this age, it is likely at you could be having Thyroid problem or other hormonal imbalances. Your Gynaecologist will suggest you the appropriate investigations to clinch the diagnosis. Accordingly you will have to be under treatment. I hope this not only answers your query, but gives you some more important advice. Dr. Nishikant