I need some help some sort a pro or docter (personal question)?

Right recently well last weekend i had unprotected sex with this girl and a day or 2 later my head(glans penis) of my penis has been itchy like every 1-2hrs a day its only a itch everything else looks fine well... I dno if i see a little slight rash forming on the head could this be thrush or shld i take this serously? If so what could it be....? Mature answers please! And also some times the penis it self is itchy.