12 days late or because of breastfeeding

So I'm 12 days late, I got my period right after having my son, I had to pump exclusively for the first three months, until he latched. I've only missed 1 other period in my 9 months pp. I was only by a week. I'm nauseous tired my back and hips hurt and I'm having cramps like I'm going to get my period (tmi) and feel like I started all wet but when I check it's just CCM. I feel like I'm going nuts we just want to see that BFP should I wait and retest in a week or assume breastfeeding made me not have a period ?