I'm not a doctor and I know this site is not a 24/7 staffed helpline, so if you are worried and unable to reach your own doctor, you should go to the emergency room, just to be safe and for your own peace of mind.
If you have been bleeding for three weeks, that is a long time. I don't know how heavy the flow has been, so again, rather than take chances you should seek a medical opinion if you are afraid or feeling sick.
I hope everything will be alright
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