Birth control question - heavy bleeding with Nexplanon

I'm currently on my second period with the implant Nexplanon, and I'm experiencing very heavy bleeding, which has never been the norm for me (before I got pregnant with my son I had Mirena). So I looked it up and of course it says to call your doctor "right away" if you have a heavy menstrual flow. But it's Saturday so I won't be able to get ahold of her, and it seems kind of silly to go to the ER for a heavy period; not to mention a waste of time and money. Just to give you an idea, it soaks through a regular absorbancy tampon - I don't have any super or super+ on hand. I'm not experiencing any severe cramping or anything else... Any advice?