I love answering that question MooMoo, it is one of my favourites. 
You are DEFINITELY not letting the side down and you can DEFINITELY be a feminist and wear whatever the hell you want for whatever reasons you want.
We had a huge thread a while back about resisting 'compulsory femininity', which meant that women who felt like it was being assumed they would do these things but didn't actually want to, or who had always done it and weren't sure why and just wanted to have a go at stopping and see how it felt, could get moral support and discuss it. But lots of very keen feminists on here didn't join in for a variety of reasons such as 'I have a hot new boyfriend' and 'I've just started a new job'. 
The double standard, where women get judged on their appearance more than men, and are expected to put in loads of effort and spend lots of money on it, IS a feminist issue, and some women like to attack it directly by growing their leg hair whatever, but as feminists we all fight on different fronts, some people have careers in male-dominated professions, others work in women's refuges, others stand up to builders who order them to make a cup of tea instead of meekly asking how many sugars they want 
Some women derive great pleasure and enjoyment from doing beauty practices and use it as a creative outlet, or the confidence they get from it allows them to go out and do other stuff. In the end only you can decide whether or not it is the right thing for you. Some of us got to the point where certain practices didn't make us feel attractive, they just felt wrong - I put on make up a few months ago and thought 'I hate this, it's not me' so I stopped but I never felt any compulsion from other feminists or like it was any effort to stop, it just felt right.
If anyone tells you you can't shave your legs etc and be a feminist they are talking twaddle. (However I would expect you as a feminist to support my right not to shave mine.
)
sorry that's a bit long, is it any use? 