Performing salaah with pus stuck on one's clothes or body

Q: I burst a pimple on my thigh to remove its pus, and just rubbed the pus with my fingers, then I wore my undergarment and pants without cleaning the pus and/or blood that got stuck on my thigh after rubbing the pimple, nor did I clean my hands. Now, some amount of pus will stick to my clothes.

Is it allowed or okay to pray in those clothes and without cleaning it (pus) with water on my thigh and fingers or without taking a shower? I read on some websites that a small amount of pus or blood is okay and it will not break the wudoo, but my question is, will the clothes become najis after such activity or shall I take a shower to make myself clean before I pray, or at-least clean only where pus or blood got stuck? 

Spotting towards the end of haidh

Q: During haidh, I have an issue with spotting towards the end. I have no fixed habit. Sometimes 8, 9 or 10 days.

1. During spotting, how often do I need to check if I am clean? At each Salaah time, or after 24 hours? Sometimes I spot, and then spot again only on the next day.

2. After I make Ghusl, say day 8 or 9, I spot again on day 14. How many days are considered as haidh? Do I fall back onto the previous month's habit?