Irregular cycle - using Glow

My period has just returned after breastfeeding. It's always been irregular, but around 5 weeks. I entered this info in Glow, then I had a 3-week cycle. I've added this period on the calendar, but Glow is still calculating my next period as 5 weeks from the previous one. Is there any way to correct this? Anyone else with an irregular cycle got any tips on using Glow?