it is actually an elaborate list of tests. based on your examination your gynaec might have suggested.
but to name a few :
hormonal tests LH, FSH , FREE TESTOSTERONE, PROLACTIN
follicular study of female, SERUM FOR TORCH infection
hystosalphingography to check patency of tubes
semen analysis males
antisperm antibody (rare cause)
laprosocopy biopsy (answers almost all questions about status in the reproductive organs)
i may be missing somethings
hope this is helpful

hi welcome to HCM.if thyroid is normal then it is not the reason for infertility now.why you are thinking that you cant become pregnant.you should always have positive attitude,it increases your becoming pregnancy.susten is a progesterone. Progesterone chances of plays a major role during the two weeks after ovulation, prior to the fertilised egg implanting in the uterus. It is also vital for maintaining pregnancy.so consult your gynec specialist and confirm your doubts regarding tablets ok

hello
welcome to healthcare magic
if your thyroid levels are normal they might not be contributing to infertility. but when you say all tests are normal it is advisable to name them as occasionally a number of tests might not have been done. clinically you and your husband must be normal and so it becomes all the more difficult to believe why this could be happening. would suggest to see an infertlity expert.
susten is a progesterone supplement which is given to induce menses when there is unreasonable delay.when you stop the tablets , menses start.
wish you good luck.
hope this is helpful