Could this mess my ivf cycle up ?

Okay so I’m set to stop taking birth control 2 day Saturday the 24th My base line is the wed the 28th come the 28th I have to pay the bill in full but i wont be sure if I can pay or not til Monday cause I don’t know if the money will be in the bank until then so I called the nurse and she won’t talk to me to explain the situation. She said this is not an emergency I just wanted to no if I could prolong the base a week to be sure I had the funds and if they wanted me to stay on birth control until I knew when I could pay She just told the receptionist to tell me that the doc will figure out mon to get off the pill but what if I get off the pill and that messes up my whole cycle cause they won’t take me wed if I don’t have the money .... I guess I have to listen to the nurse but I’m not sure she fully knows the details and what I’m meaning cause she claims it’s not a fertility emergency so She won’t talk to me herself but I feel like for me it is cause I don’t wanna prolong another month or have to wait a month then get back on birth control my meds expire and I’ll have to by them again if I can’t start until June .... long short if I get off the pill does the base have to be that exact day and if it does will I have to start over if I can’t be seen that day ... anyone have any suggestions