I don't have very much experience with this, but I'll offer my two cents anyway. I suggest that you should try to be more aware of the way you act around people. How much attention do you give to certain people? How close do you stand to them? How often do you smile when you're looking at them? Try to imagine yourself in their shoes and see how they might think you're flirting with them. Of course, it might just be that you're an attractive girl. In any case, if you want to stop giving off the impression that you're flirting, you could just act a little more withdrawn and less friendly around them, and then they should get the hint that you're not interested in them.

Flirting is an inevitable part of being alive. If you are not doing something to attract your opposite gender you would be disobeying the prime directive of Mother Nature and life. The problem is when you think you are doing something and people are bothering you. That is social dictum. Who is bothering you? People who have come in contact with you ... isn't it?

But, if you take your mind away from yourself ... you will see the spell is broken. It is our ego that creates all the problem. When we are busy thinking, "What I am supposed to get from life, or a friend, or a lover ...?" you will observe that they are not treating you right. But, what if you ask, "What can I give to another ... or how can I make someone else happy?"

It is difficult when you think you are attractive. That's ego.

By the way ... is that your painting? If so, you may posess something more alluring than your attractiveness :)).

You are bothered by this because you to feel they are being intrusive and you do not like intrusive behaviour.  Consider the old question:  "Is the glass half empty,or is it half full?"  The question is missing a third option in the questionnaire:  "Not applicable." !   That is for people who never noticed the glass and water in the first place!    You have been choosing to analyse their behaviour, and you conclude 
a) you find them intrusive, 
b) you don't like that and 
c) (wrong, very wrong!) that this is somehow all your  fault that they are being intrusive.   

So, IMHO the answer to your issue is this: Don't bother looking for these problems in the first place. Don't analyse what they are doing, ignore it.  
Also realise, what they think and feel is their problem just as what you think and feel is yours.  If they are attracted to you, so what? That is not your fault.  You are not responsible for how they feel.  But you are responsible for how YOU feel.

Is this helpful?