There isn't a law saying you must have a boyfriend at any age...
Some girls attract boys like rotting meat attracts flies and some don't. Usually there is a sexual motive to this - girls are curious about boys and boys - well boys just tend to want what boys always want...
The girls who attract boys like that usually manage this for all sorts of reasons - being very pretty, glamorous, physically matured, extrovert and probably leaving the boys in no doubt they are in with a chance...
In many ways you sound really lucky (though you certainly won't feel lucky - yet!) because what you are saying is you are averagely built with average looks - probably neither attractive nor repulsive. That is a good place to be because you won't have all the trouble of sorting out which of those "flies" only want a trophy girlfriend or to rob you of your virtue!
Mother nature isn't a fool and she produced the "rotting meat" sort of girl to protect ordinary girls like you so you can pursue interests and studies and make proper friends of both sexes without too many distractions.
The best advice I can give you is to enjoy being a young woman growing and maturing at your own pace. I can guarantee your adult personality will be better developed because of it. Don't allow peer pressure to force you to go at a faster pace than you feel really comfortable with...
Everyone has their time and you need to be confident there is someone for everyone - clearly you haven't met the right boy yet and it might be a long time before you do - or it might be next week!
If you meet people at special interest clubs or organisations you can be reasonably sure you are going to have some shared interests. If you meet someone at a party or social function it can take months to discover you don't really like them after all...
Surround yourself with friends and be patient - in the long run you won't regret it!