The best time to try to get pregnant with a baby is when you're ovulating and fertile.
The time you're ovulating and the most fertile and have the highest chance of becoming pregnant is between 12 to 14 days before the onset of your next period.
You're unlikely to get pregnant right after or a few days after your period however it is possible but if you really want to increase your chances of becoming pregnant then wait until 12 and 14 days before the onset of your next period and you'll likely get pregnant like you hoped too.