Pregnant or stress?!!

I missed my period last month, normally it would start at the end of every month. I'm 3 days late now. I haven't had sex since last December. I had a pregnancy scare around January but my period ended up coming after I was 4 days late.

Am I just freaked out or is this normal to happen?

I heard that some girls can still be pregnant and at the same time get their period....

Should I be worried?! 😥