Pp cycles

7 months postpartum and ttc again, Kinda. I had my first cycle 4 months pp then skipped a month and then had another cycle last month. My period was due a day before we last got busy. Right after I had a gush of brown blood. Next day a small gush of red, and then light brown spotting the next day then nothing. Took a pregnancy test and it was negative. Is this normal for a pp period? Or should I keep testing? I'm usually a heavy bleeder. Thanks for any insight or experiences