Spotting durring my window

Bree • I`m 27 yrs old and have one son (8). I just had our second. Not sure if we're done or not.
Had sex the other day (second day in my window) and now I'm having spotting. It looks like CM just brownish in color. I've only been off my pills for two weeks. Does this mean I'm down and out for trying this cycle? My good peak days ar tonight and tomorrow so I want to try if pissible.