Hello,
It is difficult to determine without evaluating you and your partner in person. Since it has been 4 years of yout rying to conceive naturally, you should immediately consult an infertility specialist. Also, you are 35 years old so your ovarian reserve begins to decline.
You can visit my clinic International Fertility Centre located in New Delhi so that I can guide you better. My clinic offers vared gynecological treatments and services so that you have a successful treatment. You can mail your contact details to reach you.
Next Steps
Visit an infertility specialist.