So I’m trying to get pregnant but seems not coming anyhow

I’m 33 years old and turning 34 in March

This month my period was really weird

I still have an appointment with doctor but in Jan so it is far so I need your experience

My period is late for 3 to 5 days had only the brown bleeding then it came after 5 days very dark blood and extremely painful that I was screaming ( first time) it was not a lot of bleeding then it came only for 2 days and it stopped …

Though it stopped but I still have mild period pain ..

Any idea what it might be ?