Chances of Pregnancy

Every person is different. There are many different things that could play a part in that.

If your cycle is 28 days, then that would indicate ovulation 11th May, so 6th May is the beginning of your fertile time, so there is a chance you might get pregnant.
If your cycle is 25 days, then that would indicate ovulation 8th May, so 6th May is a highly fertile day, so there is a high chance you would get pregnant.
Hope this helps

My last period was april the 6th me & my boyfriend had sex april 21st it said I would ovulate april the 20th my fertile days were from april 18-22nd I just had a baby january 27th they said my periods would go back to normal in a month I got my period in march & in april I was suppose to get my period may 4th but never did & now im 10 days late I tried taking a pregnancy test yesterday & it was negative im just wondering can I still be pregnant

If you took the test properly, it should be accurate by now (3-weeks after intercourse). Have you had sex since? Are you using any sort of contraception?
I am surprised 'they' (who are 'they'?) said your periods would return to normal. That usually depends whether you breast-feed, bottle-feed, or combine. It also depends whether you are on the pill. Anyway, I would not expect your periods to be completely regular yet, and so your ovulation would not be regular.
I would think that you are not pregnant, but take another test in a couple of days to be sure .However, false-negatives are possible, and as 'it' (what is 'it'?) said you were fertile on 21st, there is that possibility (I would have suggested you were fertile 15-20 if your cycle were regular).