Your question is quite a worthy one and appreciative as this one of the common problems in girls and young women who have sex after long periods of time or in other words they aren’t sexually active. Discharge of a little blood is quite common if hymen in vagina is not broken properly. During the sexual intercourse the hymen is usually broken but it can also remain intact for a few times and that might result in release of blood. This does not happen with every woman because women who are active and take part in physical activities and exercises have it broken during stretching of vagina.
Now coming to the pictures of herpes that you have seen it should be note that herpes happen when vagina is not kept clean and they are characterized by burning sensations not by release of blood. So there is no chance of you to have herpes or rashes in your vagina. Therefore you should not worry much as you have seen pictures of herpes as it is not your problem at all. The blood which comes out after sexual intercourse might be due to the reason that you usually have sex just after your periods are over. This is a common thing and you should not worry for it. You should also understand the fact that sometime blood can come out on insertion of penis if you are not particularly aroused properly or you are tensed. This prevents the expansion of the vaginal cavity, so it is advisable to be aroused properly and the best way of it is by fingering the vagina well particularly if the partner does it for you.
Hope you would be satisfied with the answer. Wishing you, loads of good luck.