Question about short cycle

I had a four day period 9/4-9/7 and then today (9/24) I started on CD 1 again! I’m so mad. Why was my cycle so short? My hubby and I were TTC with a fertility clinic but decided to take a break for a while (not preventing naturally). We did four IUIs (3 with oral meds and one with injectable meds). We were going to start

IVF

this cycle but hubs had a change of heart and isn’t quite sure he’s ready. I was very stressed lately, but I thought that usually postponed AF not bring it on sooner.

Thanks for ideas