It may be normal that you are not pregnant after three months of preparation, which may be due to too short a period of preparation, so you can continue to prepare for pregnancy. Pregnancy is a probabilistic event, and the timing of pregnancy varies from couple to couple due to differences in constitution. Generally speaking, women discharge an egg every month, and if it does not form a fertilized egg, they need to wait for the next month, so intercourse during ovulation can increase the chances of pregnancy. Infertility can only be diagnosed after more than a year of regular sex without contraception. Three months of preparation may be too short, you can continue to prepare for pregnancy, is a normal phenomenon. If you are still not sure, you can go to the regular hospital under the guidance of the doctor to improve the relevant examination, if found problems and then targeted treatment.