Could I be pregnant?

So, I’m not exactly sure when I would have ovulated, but according to this app I’m about 5dpo. I’ve been experiencing nausea and fatigue for about 3 days now, constant. Also my mouth has been really dry, nothing I do can stop it. My belly has been badly bloated as well, but I’m wondering if I have maybe just made up the symptoms? Also my boobs feel bigger and heavier, but not sore like a lot of people report. Is it too early to tell? Could I be making the symptoms up?