Baby Fish! Were these eggs?

[frogsNpigs]

We just added some new fish to the tank, but I now noticed there is one very tiny baby fish hiding around the sunken ship. I have absolutely no idea what fish it came from, whether it's been there or came with the new fish today. A few weeks ago, we found this by our plants. We thought it was a weird fungus or something, so we scooped it out and got rid of the plants. Were these eggs? Did we just happen to miss a few and the babies hatched? I can only see one so far, could the others have been eaten? All of my fish are tropical community fish, none are agressive at all, do they still eat the babies?

Here's a picture of the weird thing on the plants. Were they eggs?

I'll try to get a picture of the baby, maybe someone can identify it. It's only a few centimeters long, has a very thin, long body and has black stripes on its lower half. I'm thinking either a platy, rasbora or threadfin rainbow baby, but I don't know.

Edited to add:
I got some pictures of the baby. They're not that clear, but I managed to get some shots when he was sitting still. I'm thinking maybe the platy is the mom? She keeps visiting the sunken ship.

To show its actual size:

Zoomed in a little

Zoomed in more

 

[RoK]

Most likely a platy fry. Platies do not lay eggs though.

 

[Zagz]

I'd agree most likely a platy. They are livebearer's. Did you notice the platy looking rather swollen or bloated? Is the platy new to the tank? Quite often female livebearer's come from the lfs pregnant.

 

[frogsNpigs]

We did notice her a little bloated, but it hasn't really decreased much. We've had the platy since the end of August. I don't know if the baby has been around for a while, we just noticed him while looking at the new fish we bought last night that was hiding in the sunken ship. Then we noticed a tiny fish swimming under the ship. Do they normally produce a lot of babies? I've only noticed this one, maybe he's just good enough at hiding to survive. Is there an easy way to tell the sex of a platy?
This is the only platy we have:

 

[RoK]

Here's some information on sexing and breeding them: http://www.fishforever.co.uk/livebearers.html