Spotting 3 days before period

Hey ladies my period is due in 3 days but this morning I woke up with a dull pain in my lower abdomen and when I went to the toilet I wiped and there was small amount of red/pinkish blood (small amount) ( sorry for tmi) I had the same amount of blood in 2 occasions when I wiped but then it stopped and now I have very mild cramping on my right side only.

I have a unicornuate uterus also Iv been TTC for a while now.

On this time round I used pre seed a few occasions specially around ovulation and most fertile days.

My period don’t normally come 3 days early this is actually first and I’m very unsure of what to think. Has anyone of you ladies experienced this kind of problem that actually turned out with a BFP?? I would be very great full if you could all share your stories as I have no idea of if this is normal.