"Teen Mom OG" star Amber Portwood [VIDEO] is currently pregnant and there have been a lot of questions about the paternity of her unborn child. Fans that have been following Amber's pregnancy have questioned whether her baby is really fathered by her new boyfriend Andrew Glennon or if Amber might have gotten pregnant prior to her break up with Matt Baier. Considering their issues and the fact that Matt is already married to someone else, that could make things very interesting.

Why do fans think the baby might belong to Matt?

Amber Portwood [VIDEO] and Matt Baier had a very rocky relationship that ended at some point in the summer.

Amber didn't confirm that they had split up until August, the same month that we all learned she had started dating someone new.

Recently, Glennon revealed that Amber's due date is May 13. Immediately, "Teen Mom OG" fans ran for their pregnancy calculators and started figuring out when Amber may have conceived in order to have that due date. The answer to that question would be on or around August 20.

So who was Amber Portwood with during the second half of August? Considering that she only told "Teen Mom" fans that she had split from Matt in August and then introduced Andrew the same month, it isn't too shocking that everyone is asking questions about the paternity of her baby.

Even Gary Shirley gets involved

Even Amber Portwood's ex has gotten involved in the paternity guessing game between Matt Baier and Andrew Glennon. As rumors swirled that Matt may have fathered Amber's child, he spoke up, hoping that Matt wasn't about to father a sibling to his own child, Leah.

During the new Monday night episode of "Teen Mom OG," Gary Shirley discussed Amber's paternity drama and the probably of who fathered her child.

"It had to be within a week of them hanging out," Gary said of Amber and Andrew. "Hopefully, it's not Matt's [baby.]"

That's when Gary's wife chimed in, "I think there was a break between Matt and Andrew. I think. I don't know."

Amber clears up the rumors

However, Amber Portwood caught wind of the paternity confusion and decided to address the rumors herself. She made it clear that her unborn child can't possibly belong to Matt Baier because they weren't even together when she got pregnant. She even told "Teen Mom OG" fans on Twitter that they split up in May, only revealing their break up was permanent in August.

Amber even went a step further to make sure that fans knew the paternity rumors weren't true. She said that Matt moved to Las Vegas in July, leaving her behind so it wouldn't even be possible for him to have gotten her pregnant in August. It looks like Gary Shirley's wife may be right and that Amber got pregnant with Andrew Glennon's baby not long after the two met.