These are not because of pregnancy. It can be because of many other reasons. As mostly pregnancy appear after missing periods. U need to do intercourse from 9th day of her cycle (counting first day of period a s day 1), to 15th day of periods (if ur cycle is of 28 days). DO every day or every alternate day
Also Getting children is a long process.
“Even for a healthy, fertile couple, the 'per month' success rate is around 15-20%, so it is not at all uncommon for it to take some months to conceive. Overall, around 70% of couples will have conceived by 6 months, 85% by 12 months and 95% will be
pregnant after 2 years of trying.” Eventually it will happen.