Strong early symptoms: twins? Pms? What?

Alright so ive been having “symptoms” since 3 dpo (probably just me imagining them tho) but stArting this morning (6dpo or so) I woke up with that nausea/ salivating feeling. And that continued for a while, then went away, then came back in the evening. Also: my boobs HURT. Like in my chest. Not my nipples but like armpit/chest area I guess. Not to touch, just inside feeling. Shortness of breath, occasionally feels like my heart is racing slightly. (The shortness of breath has ONLY happened when I was pregnant) Well my question: anyone feel these strong feelings so early and have it be twins or something? I’ve had 2 other kids and never ever felt this soooo early and strong. So I’m just curious. Oh and these are 100% not my normal pms symptoms.

Other symptoms (but could be pms - even though I’m 7 days away) : fatigue, congestion , allergies, and extreme moodiness