What Could Itchy And Tender Vagina Post Sex Suggest?

I often find that following sexual intercourse I get a slight irritation at my vagina. It isnt painful as such, just slightly tender and sometimes a bit itchy. It usually only lasts a couple of days but is more intense after having sex more than once in a day. I know it is not and sti as my boyfriend and I were tested before sleeping together and I have had a yeast infection before and this feels different. Is this normal?