Is missing tahajud a sin?

Q: When my brother in law's wife was pregnant, I said that if she gives birth to a baby girl I will pray tahajud namaz everyday. But later I felt guilty about this and few days later she delivered baby girl. 2 months later I became pregnant and till I maintained tahajud namaz I was safe. When I did not pray tahajud the next day, I had to undergo major surgery. It was ectopic pregnancy my tube was ruptured. I think that God punished me. I sad sorry from depth of my heart because I took tahajud namaz lightly. Will Allah forgive me or not? Will I be punished my whole life if I don't pray tahajud? 

Spotting after haidh

Q:

1. If a woman has a regular period habit of 7-8 days, and she, on the morning of the 7th day, cleans her private area, waits a bit, and sees dryness so assumes her period is over, then later on in the 7th or 8th day she sees spotting (red, brownish and sometimes yellow discharge). Is this menstruation?

2. Is it menstruation if I see this sort of spotting after the 8th day (last day of my habit)?

3. Do I have to make ghusl/pray between spottings? I tend to get spotting for a few days after my period ends and I would have to make ghusl 3-4 times back to back (sometimes on the same day) if it is considered menses because the spotting comes once and then it is dry again.

4. Lastly, I normally get yellow discharge throughout the month. Most of the time it starts before the 15-day period of purity is over(after the end of one menses) and lasts all the way to my next menses. This yellow discharge tends to intensify 6-10 days before the start of the actual menses/blood, which then lasts 7-8 days. Is this yellow discharge considered menses? If this yellow discharge is considered menses, then do I consider the last few days of the actual blood flow not menses? How long can a menstrual cycle last in the Hanafi Madhab? 

Synthetic hair

Q: I wanted to know if synthetic hair is permissible in Islaam and if so, what can and cannot be done whilst having this type of hair on one's head (i.e. reading Quraan, etc.)?