A few charting questions

Hello everyone

This is my first post since TTC my DS who has just turned 2, and I was wondering if anyone could help me with a few questions.

First time round TTC, it took us 11 months to fall pregnant, so this time around I decided to start charting straight away, just so i could find out what my body is up to, and also because I quite like charting - geek alert! :redface:

I have been using the same thermometre that I used when I was TTC two years ago and am not sure that they are that reliable over that time period. Does anyone know if they should only be used for a certain period as my temps seem a little odd?

I haven't been on the pill since giving birth, and stopped breastfeeding at 8 months so I think my cycles should be pretty much as regular as they are going to get but like I said before, there are some weird temp spikes that don't seem right. Chart is here My Ovulation Chart.

I also have some spotting questions. After a couple of days of brown spotting (6 & 7 DPO), I had a gush of red blood at 8DPO, although it was enough to be classed as light, it seemed different to a normal period starting and appeared tinged with CM - it then stopped completely that night, but resumed again the next night. Again red but only for a couple of hours. Since then I've have nothing but vaguely brown tinged CM. I changed my chart to reflect it as spotting rather than CD1 because it just doesn't feel like a period. Most sources I can find have said that implantation bleed is not that often red, but I was wondering whether anyone has experienced that or whether it is a possible sign of a chemical - although I would have thought I would have bled for longer?

Thanks, would appreciate any advice.