Totally freaking out!

Sooo... a little back story. Me & my boyfriend have been together for 5 years almost 6 and we’ve been talking about kids but we’re young. We’re only 21. Anyways... I am 8 days late on my period and i have been feeling off. I have headaches and my body aches. I took a test already but it was negative. I dont know what to do 😩😩.