2 Day Spot ?

Asia

I’m on bc (nexplanon) and haven’t been tracking my periods 🤦🏾‍♀️🤦🏾‍♀️I had a 2 day spotting on the 18th and 19th. On the morning of the 18th I saw light pink and put on a liner. One wipe and it was gone. Didn’t see anything else for the rest of the day. Same for the 19th. I’ve been having PMS symptoms since the beginning of this month. I’ve tested 3 times, all negative. It’s been a week or so since I’ve last tested. Any thoughts ?