Femara ovulation??

Hi all! I started taking 2.5 femara this month and am currently on cycle day 10...I usually have 38ish day cycles, with expected late ovulation. I took an ovulation test at 630 am today (cd 10) and it was blaring positive to me. This seems really early, considering I have long cycles. Is this common when taking femara? Has anyone have had multiple LH surges on femara or do you guys anticipate this is inaccurate because it’s so early in my cycle? Maybe femara will shorten my cycle??