I only had the Nexplanon in, in August 2013, and had it out Monday (6th January 2014). So I had only had it in for about 5 months. How soon will my periods return?

The nurse was reluctant to take out my implant because I'd had unprotected sex a few days before removal because I could still get pregnant. 

I also had unprotected sex on Tuesday (7th January 2014)

I started spotting yesterday but that seems to have stopped now... I don't know what will happen, and I'm quite scared of being pregnant.