Speaking from having looked at tons of pictures when researching gential piercing & from previous girlfriends I have had..trust me..they come in all shapes, sizes, a variety of colours, different amounts of lubrication, different smell to them, hair or no hair. There really isn't such thing as a 'normal' vagina.
The most variation usually comes in the labia minora (inner lips/labia) which can be tiny and barely noticable (like most girls you see in porn films..not like the majority) or more prominent and have a wavey or rippled look to them. They can vary in colour from a light pink to greyish (and every shade in between).
I think it's sensible to have a check up if you are worried. As for going twice in 1 week. They are big on confidentiality so don't worry about returning without your friend, they will understand and respect the fact that you wanted privacy.
On another note, you should take the time to properly get to know your body once you are sure everything is OK. It is important to know how your vagina normally looks and smells. That way if there is ever a problem you can spot it early on. Same as periodically checking your breasts for anything abnormal. There's nothing gross about fulling checking out your equipment. Plus you can take comfort in the fact that it looks a heck of a lot nicer than what men have hanging off the front of them..the last chicken in the shop look!