According toPeople, a follower asked Burgess whether she and Green had been trying to conceive.

“I was on birth control,” she wrote.

“We were thinking of trying mid to late this year lol.

Sharna Burgess

But the Universe made her own plan, found a window and went for it.”

Birth control, unfortunately, can fail for any number of reasons.

The major reason,Voxexplains, is human error: people forgetting to take their birth control pills.

Sharna Burgess

Combination pills are a little more forgiving.

In that time, “you may not be protected from pregnancy.”

When theystop taking the pill, their normal period cycle will resume.

If she had been taking over-the-counter allergy medication, the efficacy of Burgess' birth control could have dropped.

“I personally noticed that pseudoephedrine causes breakthrough bleeding,“Dr. Sophia Yenexclusively told The List.

“Pseudoephedrineis most commonly known as Sudafed.

But there could be another reason why Burgess ended up pregnant: her genes.