should i be worried?

i had sex two days ago and now since then i've been having this weird ache. when i walk down stairs it feels like my uterus is moving up and down. when i push to go pee, it feels achey and sore.. it's only my second time having sex so i'm still not sure what's normal and what's not. i heard sometimes it hurts to walk but is it supposed to hurt in my lower abdomen region as well?