TTC #2 while breastfeeding

Hey all! So I’m currently breastfeeding and I just recently ovulated 5 days ago. So I’m 5DPO I’ve been feeling kind of tired nothing insane but my nipples are super sore which only happened to me once ever when I fell pregnant with my first. He doesn’t bite or pull my nipples when feeding so I don’t feel that plays a role and I never get this feeling when I’m PMSing. I knows it’s only 5 DPO but could it be a pregnancy symptom?

UPDATE: I’ve been super moody a little bit more tired and my toddler (whom I’m still breastfeeding) has been having diaherria these past couple days...my milk supply seems like it maybe taking a dip but I took a pregnancy test out of impulse yesterday and it was negative 🥴 it’s only 7DPO. What do you ladies think?