First time IVF question ..

So I am going in tomorrow to have my beta done for my IUI. I am 90% sure that it will be negative. My husband and I have decided that we will be moving forward with IVF if I am not pregnant tomorrow.

My question is when do you think I would be able to start? I have already completed all of my lab work, had a synohystogram etc. My period should start Sunday if I stop taking my progesterone tomorrow. Do you think there is any chance I will be able to start this cycle or will I have to put a cycle in between. I know my fertility clinic likes for people starting Ivf to have their period start on the weekend, so this would be kinda ideal. Well wishful thinking anyways. Hopefully my beta is just positive tomorrow. I’m just excited to start IVF , I’ve been ttc for over 2 years I just would not like to wait another cycle to start.