To reiterate what others have said, you can never lose your virginity to yourself or to a toy. If you have not had sex with another person, then you are still a virgin.
Your future partner will not be able to tell if you have had sex or masturbated. Masturbation and sex don't really change your body.
As for hymens, most girls break them long before they ever have sex anyway. Most hymens are broken in childhood or early puberty due to masturbation, tampons, or running and jumping. It often does not hurt or bleed when the hymen tears, so some girls have no idea when it actually happened. That's ok though. The hymen does not actually do anything. It is just a piece of skin that is leftover from when you were still developing in the womb. Hymens have nothing to do with virginity. Like I said, most girls tear them when they are still virgins. On the other hand, a few women have really tough hymens that don't tear at all, even after they have had sex. Some girls are also born without one.
For more information on the hymen:
http://www.coolnurse.com/hymen.htm
For more general sex and masturbation information:
http://www.coolnurse.com/sex_faqs_index.ht
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