it would be a great idea to see a doctor at a local clinic (GP or Family Doctor) for the symptoms of anaemia..
the main concern in your question is the part about the headaches and dizziness which could be related to the large amount of blood loss of which it is bad enough could cause fainting spells, chest pain, chest tightness, difficulty in breathing and at extreme cases, cardiac arrest (heart attack)..
you do NOT want to faint while crossing the street or riding a bike..
due to excess blood loss, you may have low blood pressure, anaemia or both; and either two can cause cardiac arrest on its own if it was severe enough.. and yes, admission is very much expected if you have extreme low blood pressure, severe anaemia or both..
i cannot tell you in a good conscious to wait until your Monday appointment with your OBGYN doctor - it feels a lil bit to far to sit around and do nothing.. but at the same time, i do not want to look foolish or to sound like an alarmist, to advise you to go to the emergency department (the ER or the A&E) without knowing more..
but i will tell you this..
if you were my daughter, i would prefer to look foolish and take you to the ER immediately, than to be sorry and have you fainting somewhere with no help near by..
go to the ER.. and tell them about the dizziness and the headaches.. this would 100% trigger them to investigate your blood pressure and your haemoglobin level (how far the anaemia is at)..
all the best..