Finally got somewhere with the doctor

After nearly two years of actively trying and four years of unprotected sex with my other half my doctor has refered me to a fertility clinic- I have a 6 year old already and my partner has  children from a previous relationship, (he is older than me) he has to provide a sample while we wait for the referal to come through but can anyone tell me what to expect? Do u think we will be eligible for help even though he has other children? I feel like a weights been lifted but is still hovering! Just hoping this referal doesn't take forever!! TIA x