It is wishful thinking I am sure~

My history:
DD is nearly 4. DS is 19 mths. I am breastfeeding.
I had one period between DD and DS.
What I think was AF came for the first time since DS on Dec 29 2010. It was a fairly light, symptom free period...it was day 3 before I was convinced it was a period (before that I was hopeful for implantation bleeding)

I was always a 28 day cycle before.

Oh how we BDed this month! one happy DH.


Based on previous cycles, I expected AF on 26th Feb. Still no AF. No premenstral signs or MS (etc) and about 10 negative tests.

What I would like to know is:

Is it possible that 4 days late = preg despite neg tests, or by this stage would pregnany be detectable?

Did your period come back regular? or did it take a few cycles to regulate?

If I were to start charting (on fertility friend) would that be helpful for TTC, even when no periods?

I don't like being unpredictable! Now that we have decided to add to the family, and now would be the same gap as between DD and DS, I am afraid I am going to worry myself to infertility (IYKWIM)