Idk why I’m feeling like this lately😕

I started having brown discharge last Saturday and someone told me it was just old blood from my period. Today I am 6 DPO. I am feeling EXHAUSTED. I slept all night last night woke up around 11:00, got ready for the day. Went to my boyfriends friends house & ended up falling asleep in the car for an hour without even knowing it. I shouldn’t be tired, I slept a ton. Yesterday around 6:00 I started to randomly feel dizzy, uncomfortable. Got home laid down and felt okay. Before I fell asleep today I was sitting down and got some light cramps on my left side for a couple of minutes and went away. I’m really thirsty all the time, I been drinking water like crazy, I feel like I been more hungry than usual. I don’t want to get my hopes up, but I feel different.