TTC but scared i cant...

Im scared i cant have any more children. I have a 2 year old from a previous relationship and shes happy and healthy, but im in a new relationship and got my nexplanon taken out around may something this year, well my boyfriend and i have been trying to conceive for about 4 months now with no luck. I know he can have babies because he has gotten his ex pregnant 2 times, but they were unsuccessful.. 😔😔 sad day. But im just scared my body wont wanna have babies. Were taking pills to help out. I did have a complicated labor/birth with my daughter. Im just sad. My doctor said that there is no way i cant have more babies because ive already had one.. but i dont know. Please send advice and baby dust