OPK help

Gina
Hi everyone. 
Do you think this OPK is positive? It's the darkest I've had this month. I'm cd18 with normally a 28 day cycle. Last month I had a positive on cd16. 
My husband and I BD'd this morning (11-12hrs ago). Will I be ok BDing again tomorrow morning (in 12hrs) or should we do it again now? We are both suffering with colds but will give it a go if you think it will increase our chances haha. 
G