Can you have a period a month or 2 after you get pregnant?

Sabrina • Married 💍2019, pet parent to 🐕 Frozen Oreo

So I was told by 2 people that when they got pregnant they didn’t know because they had a full period or 2 and then later they found out they were pregnant. The first women said she went 2-3 months and didn’t know. And the second said she had 1 full period after she found out she was pregnant.

When I looked it up it says on Glow and other apps like Flo that its impossible to have a period. I know she was telling the truth because 9 months later of course she had a baby lol.

I’m asking because I don’t think I’m pregnant however I rarely vomit and I vomited twice this week. Once on Monday around 8pm and again on Friday (yesterday) at around 10pm. On Tuesday I took a pregnancy test and it was of course negative (it’s always my luck). Didn’t think anything of it until yesterday it happened again and now I’m kind of freaked out. I would love to be pregnant however the tests are coming back negative so I’m unsure.

I can’t just go to the doctors because I have no insurance so just wanted to see how common it is to have a period and still be pregnant.

Any thoughts?