The actress's character has in recent episodes become pregnant via a sperm donor and discovered that her unborn daughter is at risk of having Down Syndrome.
Lynch has now revealed that she is unsure about the scale of the plot and joked that the father of Sue's baby may as well be Antonio Banderas.
"I know that Sue's supposed to give birth in September, so whether that happens before the fourth season starts or in the off-season I have no idea," TV Line quotes her as saying.
"There are many [variables]. I could lose the baby. I am 51, so it's a risk and they already [established there could be] some abnormalities in a previous episode."
Lynch previously teased that Sue may become a villainous character again, saying: "If something p*sses her off she could switch."
Glee airs Tuesdays at 8/7c on Fox, with the season finale scheduled for May 22. The show airs on Sky1 in the UK.
Watch Jane Lynch discuss the pregnancy plot with Access Hollywood below: