Hi, Thanks for consulting us. If you had a miscarriage in the past & it is proven by lab tests, then probably you may conceive naturally again. Natural conception needs ovulation, patent tubes & availability of good quality sperms at the right time. There are many other factors involved in this process. Three years is a reasonable time & you should consult a good fertility specialist or a consultant Gynecologist in your area with your husband for full evaluation & specific treatment. Wish you all the best.