Worried...

So the obgyn office I goto they’re always rescheduling appointments , not answering the phones or putting you on hold so long you say fuck it and hang up and they don’t bother to call you back well today I finally got ahold of them to book an appointment well the appointment I got is for oct 1st and I’ll be 20 weeks I have not been seen by an actual doctor yet I did the first appointment where they ask you health questions and give you a slip to go do blood work and one other appointment for a dating scan , I feel like that’s not ok them seeing me half way through my pregnancy cuz like I said they rescheduled my appointment I had to meet with my ob to a day that worked for them which I couldn’t make obviously since I couldn’t pick my own time and date I have 3 other kids so I’m very busy so I work around them but is this normal or not I feel like that’s late to be seen by an actual ob.?