Ttc first time..

Brook
I had my Mirena removed in February.
My boyfriend and I have been ttc since..
Right now my cycles are showing me 38 days apart when my AF is supposed to be here on the 15th of May. My most fertile day was Monday, but we BD yesterday.. And then last night I had very very little light pink spotting. And then this morning it's between light pink and brownish.. But still very light.. I'm confused on what is going on.. We have been really hoping to have a baby and I have been taking prenatals.. Any ideas?!