Cycle length is messed up

Jade • ⚫🍭Happy wifey|step-mommy|TTC baby #1 with Follistim injections🍭⚪
My information has that I am on a 28 day cycle (which I am) but now glow has me on a 29 day cycle which has me all confused..it says I am on cycle day 24 which would mean I would start on the 6th but glow has me starting on the 8th I'm really confused. Can you help me please. I really need this fixed because this cycle I am starting Clomid and I really need my ovulation to be accurate. Thank you