Hi, I am 21 and I have been having irregular periods

Patient: Hi, I am 21 and I have been having irregular period. I had an intercourse on 22nd of dec and took postinor 2 as prescribed (I was on my period when I had sex and took the pill) so the period extented for 3 to 4 days more. For the month of jan I missed on my period and had it on 2/3rd of feb and now it’s almost the end of the month and I have not had my period. I don’t have any pregnancy signs just that around 26th of March I had a slight cramp and back ache which usually happens before my period but there Is no sign of period now. Can I be pregnant or is it the side effect?Thanks in advance

Doctor: Welcome to Ask The Doctor.We are here to help you.With the history given by your, pregnancy is very unlikely.How ever, you should get your workup done for irregular periods.These problems can occur as a result of hormonal imbalance, excessive stress, Polycystic Ovarian Syndrome (PCOS), Thyroid issues.I would advise you to get investigated.Get following investigations done:1. Ultrasound Pelvic organs.2. Thyroid profile.If any issues are found you would be treated accordingly.Share my opinion with your doctor.I hope it helps.Stay Healthy.