With my first:
sore, swollen breasts started very early-soon after conception. Nausea and food aversions started soon afterwards (I could only eat fresh fruit, Gatorade, cold cereal, and spaghetti for a few MONTHS with her...I couldn't stand to smell anything else, either. )
With my second:
Nothing. No sickness, no sore breasts, nothing. I didn't feel pregnant. The only reason I tested was because I was late...and I didn't even really believe it until the doctor confirmed it-because I had no early symptoms.
With my third:
I woke up in bed the night of conception-a couple of hours after-and KNEW. I woke straight up out of bed. It was probably the second the egg got fertilized.

I felt nausea IMMEDIATELY at that moment. Soon after, the sickness/nausea started, and the other symptoms.
I never really got crampy with my kids...but I did have light spotting in the first month or two with them both. (Around when my normal TOM would have been.)