Your question is an appreciative one. Let me tell you that you have involved yourself in a very dangerous practice because having sex with seven different partners in a small period of time might lead you to blood transmitted diseases like the HIV. The irresponsible behaviour you have shown is quite unnerving can as this can turn into AIDS. Since you are young there was no need to do this. You have done also taken part in anal sex and let me remind you the most infection of AIDS is caused by mating with an infected partner in anal sex. You asked that you fear that you might contract and STD or any vd but these are not as dangerous as is the HIV. There may be a chance that you might contract a vd but HIV chances are more so to say. If you have had sex with a non infected partner then you could be safe and you will closely sneak out but there is a rarity of it. Therefore the first thing that you should do is to get the oral HIV check up that is done by a sample of saliva. This test takes about 20 minutes and provides you with accurate results. You have to keep in mind that you don’t have to engage yourself in any kind of unprotected sex if you sneak out this time. This is highly dangerous and absolutely uncalled for. Hope you stay healthy.