LH and FSH blood tests

My cycle varies but on average is 34 days. I had "my" day 21 LH blood test on day 24 and  results showed 3.5. I'm booked in for my day 3 FSH blood test on Wednesday as due on today. I haven't come on yet but feel like I'm going to maybe tomorrow. If I do, shall I keep my Wednesday appointment/ push it back to Thursday or Friday or are my dates completely wrong and do I need to start again next month? Is my LH result likely to be wrong if my dates are out?