<s>[INST] I have thyroid 5.90 I have been told to take thyroxine25 half tablet a day,I got my periods last month on12th june,i had ealier done a coursr of diane35,after the course i got my perios 4days late,this month i have not yet got it at all,i have also done pregnancy tesy,its negative,I want to get pregnant ,me&my husband have started planning,I want your advice whether thyroxine tablet is correct and should I start taking folic acid,if so then what tablet to take for folic acid,I m very worried what to do for my periods,help me,im nt able to sleep in the night as well.i am taking thyroxine also regularly.i have yet nt got my periods,what to do to get it and what medicine should i take for folic acid [/INST] Welcome to Healthcare Magic You can wait for 7-10 days late for periods to come as periods can delay even with stress. Firstly get your thyroid hormone levels checked. If it is normal or you have hyperthyroidism also you can have irregular period or missed period like this. But since you are taking Thyroxine you should rule our Prolactin hormone elevation and Polycystic ovarian disease by thorough checkup by Gynaecologist if your periods do not come. If Pregnancy test is negative, no need to take Folic acid but if you are planning for pregnancy you need to have regular periods first which ca be done by contraceptive pills provided by Gynaecologist advice only. Get thorough checkup by Gynaecologist to rule out any hormonal or ovarian problem. </s>