For me, it was so much easier falling pregnant after my first. Before DS1 was conceived, my DH and I had been trying for nearly 2 years. 3 months after DS1 was born, I fell pregnant with DS2. When DS2 was 8 months, I fell pregnant but it ended in a miscarriage at 11 weeks but 3 months after I fell pregnant with DD. When DD was 6 months, I fell pregnant with DS3. We were not trying for more children after our first so the rest were unplanned. I guess everyone is different.