Help!!!!

I have been currently trying to conceive and breastfeeding. I had either a faint line or indent in my last test last month. But then we had sex and I bleed. On and off for a few days. Then spotted for two. This period was very very odd for me. I’ve had a consistent period since my son has been born. All the same. And now it’s the next month and I am six days late with no symptoms. What is going on?

The only changes in my life is my son now almost sleeps through the night. And my fiancé works in another state.