Please help spotting everyday after positive opk

Had positive opk and then two days later I started light pink spotting only when I would wipe...... I know it's too early for implantation but could this be low progesterone or something? I know when we did our IUI last time I had low progesterone... Unexplained infertility 5 years ttc #1.. Please share thoughts or similar experiences.. I have a little cramping but it could be my head playing games lol.