Serious question about plan b... do I need to go to the ER??

Okay I took plan b Thursday night at like midnight... I was totally fine the first few days well yesterday I started barely bleeding... and today I’m bleeding like a lot like a period .... I just had my period for over a month... and it ended last Tuesday when the mishap happened.... I have nexplanon so it makes me bleed quite a bit.... well now I am bleeding quite a bit and I am worried... I feel tired and run down... is this okay??? Or is this not normal? My friend scared me and told me I could die so I’m freaking out rn at work please help.