What Causes Light Pink Spotting After Taking Pregesterone?

Hello,My husband and I have been TTC for 13 months. My cycles are very predictable unless I am on a medicated cycle with Clomid/estridol/progesterone. Today I am one day late and I tested negative for pregnancy. However, I took a single progesterone suppository two nights ago because my symptoms were strong and I was having a very small bit of light pink bleeding. My question: can taking 1 progesterone suppository delay my period?Thank you!