When does morning sickness start ?

I'm not a pregnant gal but I can definitely tell you that morning sickness is anything but mandatory. It does not happen in every single pregnancy.

I'm not nor have ever been pregnant, but I'm fairly sure it starts between the 4th and 6th week of pregnancy (if it's going to happen at all).

Another never preggers woman here, but...

you ask if you can have morning sickness before ovulation.

that would mean you're not pregnant.

Right, that's the point I was going to make too.

As for when it starts, for me it was one of the very first signs that I was pregnant. It started very early and hung around for about the whole first trimester.

It's very individual though. If you know you're pregnant and you haven't experienced nausea yet, that's not necessarily a problem. If you're not pregnant and you've experienced nausea, it doesn't necessarily have anything to do with pregnancy.

Why did you want to know? (Just in terms of providing the info you're actually going for...)

Morning sickness usually starts around week six of your pregnancy or the third week after conception. But because every pregnancy is different it can vary from woman to woman.