Should I test ?

Brittany • Christian Mother , & wife ,baby number two Due march 27th??
I had strange spotting at 9dpo , and then the following Monday at four days late I had what I thought was AF , however it was so light that wearing a tampon wasn't even necessary .  I'm so naseous this morning , I have a FRER and I'm debating on using it ? I know if I am pregnant it'll definitely detect it by now .