Irregular periods, want to conceive. Tests done. Taking Thyronorm. Prescribed with Ovral. Will Ovral hinder conception?

Dear Dr Hi I am 34 years old. My MC was fixed of 28 days. it had never been irregular earlier but now I am suffering from irregular periods from last 9 months. I have never taken any contraceptive pill till date. Numbers of U/s done. All reports are normal. My PCOS test is also negative. I have 6yrs old son and one medical abortion two years back. My Estradiol E2 is 43 Pg/ml, FSH is 10.15mIU/ml and LH is 14.56 Miu/ML. All these test reports are 2nd day of Mestruation cycle. Right now I am taking thyronorm 25mcg as TSH was 5.68 uIU/ml. All my tests are normal Blood pressure blood sugar etc. I want to concieve second child but due to irregular periods I cannot concieve. Dr told me to take Ovral l tab for month. I am confuse as this a contraceptive pill and want to concieve. What to do? please guide