This is based off of LeoHamato226's tmnt mpreg fanfic. I hope you like it Dude/Dudette!

Flashback

Leonardo sat on the bed smiling softly as he felt the twins he was carrying moving. Leo walked in the room to kiss Leonardo. Leo smiled as Leonardo placed his hand on his growing stomach. "I love you Leonardo. Nothing can change it" Leo said. "I love you more" Leonardo said. The twins kicked and Leo laughed. The family's healthy, nothing can change it. Or can it? Leonardo is eight months along in the pregnancy. He's showing a lot. Smiling, Leo sat next to his mate singing a soft lullaby. (Warning! The feels)
"You are my sunshine, my only sunshine. You make me happy, when the sky is gray. You never know dear on how much I love you, so please don't take my sunshine away" Leo sung as Leonardo smiled with tears running down his cheeks. "Leo.." he was shocked on how amazing Leo sung. Leo kisses Leonardo softly as they cuddled.

A week later

Leo sat next to Leonardo who wasn't feeling well. "I know what is wrong with Leonardo," Donatello said. "What is it?" Leo asks. "Leonardo has a disease called Scarlett Fever." Donnie said. "Scarlett Fever? Could that kill the twins?!" Leo asked. "Technically, yes, but if we can get the twins out of Leonardo in time there's chance that one of the twins will live" Donnie said sadly. "Oh" Leo said. Leo ran to Leonardo who was trying to wake up. "Leonardo," Leo spoke. "Leo, do they know what's wrong with me?" Leonardo asks. "You have Scarlett Fever, we have to deliver the twins as soon as possible." Leo said looking at the sad Leonardo. "Well you're just in luck, my water broke!" After birth.

Leonardo gave birth to both twins. But died in the process of birth. Leo sobbed when he was told that Leonardo didn't make it.
" Failed, I can't live without you... " Leo whispered. Then a young male walked in. "It isn't too late. You can save him. By using this" The young male said holding an all silver syringe. "What's in this?" Leo asked. "Vampire venom, just stick it in his chest and let the venom do its job." The male said. "What will happen to him?" Leo asked. "He'll turn into a vampire when the venom has spread." The male said calmly as Leo nods and did what he was told. Within an hour or so, Leonardo woke up with bright red eyes. "Leonardo? Baby? Are you ok?" Leo asked worried. "I'm fine." Leonardo  said, his voice sounding like bells. Leo smiles but was shocked on how his love sounded. "Wow, I sound like this now?" Leonardo asked. Leo nods sadly but smiled because this can be an advantage on Shredder. Of course, the twins were a boy and a girl. So they named the twins: Tyson for the son and Tang-Shen Jr. They all lived in harmony since then. Leonardo was trained not to harm Karai since she was still human.

  Sorry if this took to longLeoHamato226, I was super busy with other stuff so here you go!