salam.
a girl gets dried tiny pieces of blood mixed with white, on the date when her period is supposed to come (or 1 or 2 days before or after),they are not found everytime. sometime its noticed once and sometimes more than once, ...this last for atleast 2 days.
what should she do?
does she hvae to take bath and pray when she finds her self clean or those pices are not considered as menses at all.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

These blood clots are considered menses since that girl sees them during the period of menses provided that there is a gap of 15 days or more between the time of seeing them and the time she became pure from the previous menses. All this is menses if it does not exceed the time-period of 15 days even if it exceeds the regular days of menses according to the preponderant opinion of the scholars .

Therefore, that girl should refrain from praying and fasting when she sees these clots of blood, and she is obliged to perform Ghusl when she sees that she had become pure.

For more benefit, please refer to Fataawa 91444 and 98693.

Allaah Knows best.