Disguising my roots

[TheOnlyPersonInTheRoom]

I don?t know if it?s even possible but if it is I?m sure someone on here can help.
I?ve had highlights for years and I?m not even that fussed about having them any more (because it only looks nice for about 2 days) but I get to the point where the roots look so awful that I just end up getting them redone and starting all over again.

Anyway I?m pg now and, AIUI, I can?t get my hair dyed.

Is there a way of making it look reasonably decent without getting it officially done at the hairdressers? I don?t mind shoving products on it or paying for whatever (though I?m not very good with hair?). I have a professional job so I want it to look reasonable but I can?t wrap a bandanna round my head or anything like that. WWYD?