I'm ment to take my seritide preventer every day but I'm starting to forget it but I don't no what will happen if I do forget it Or stop taking it
Proventil is short-acting. If you forget to take it you might wheeze - or you might not. The schedule, as such, is not that important. Keeping yourself free of symptoms is. So if you forget to use the inhaler, and start to wheeze, then take a treatment, whether or not it is according to schedule.
What confuses me is that inhalers are usually used on an as-needed basis, in any case.