I Have A Slightly Itchy Penis And Some Very Small

I have a slightly itchy penis and some very small red marks. They appeared about a day after having sex with my girlfriend when she was a bit dry. She isn't normally. I don't think it's a std because I was checked out with a full test when I met my girlfriend and I haven't been unfaithful. I have tried putting on canesten , an anti fungal cream but not regularly because it makes you feel a bit slimy. Can you help please?