Carers Allowance and Self employed

[monkeywithacowface]

My son gets middle rate DLA so I am able to claim for carers allowance if my earnings are below £120 per week. I am self employed and typically work a set amount of time each week and earn slighty over the threshold. However my contracts are with schools so I do not work school holidays so if I pro rate my earnings over 52 weeks it does come under the threshold (just).

My question is as I've only recently started out and have no self assessment to show proof of earnings yet, how would they work out if I'm eligible. Also if I were to go over the threshold (not likely but possible as it is quite tight) what would happen in terms of paying it back or informing them?

Sorry not sure that makes sense It would help us a lot if I could claim but would be worried if when I came to do my self assessment it averaged out at more than £120 per week!

Sorry £116 not £120

This is on Carers UK website:
If you are in employment and have fluctuating earnings it is possible for your earnings to be averaged out over a recognisable cycle of work or over five weeks.

If you are in self-employment your average weekly earnings are normally calculated by looking at a specific trading period, which is normally a year. However if you have only recently started your self-employment, or if there has been a change in your circumstances, then a different period more representative of your average weekly earnings can sometimes be used.

The following amounts are deducted from your gross weekly earnings (if you are in employment) or your net profit (if you are in self-employment) before your earnings are taken into account for Carer’s Allowance:

Income Tax
National Insurance
half of your contributions towards an occupational/personal pension

Thanks I'm wondering then if they regularly review rather than wait until the end of the tax year I'm less likely to go over?