25 days late

Hey everyone im new to ttc and i have irregular periods that this app hasnt figured out the pattern! i never really know when my period will come but for some reason i have this gut feeling that in pregnant! i test four weeks ago and they were negative but according to the app im 25 days late and im nervous to take a test. I have been super tired lately to the point where i an able to sleep the whole days and i wake up super hungry and i feel like i have to throw up sometimes but dont. What do you guys think?