Pregnant Swordtail?

I currently have 2 Swordtails in my tank, both of which I thought were male due to the fact they both had the Sword on there tails. But today 1 of them seems to have developed a bit of a bump?

Could it in actual fact be female? Or could it be something else

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If it’s got a sword it’s a male also males have a modified anal fin known as a gonopodium

Ahh right, neither of mine are female then, well the 1 I thought may be pregnant does not look in a good way at all anymore, hanging round the filter and looks as if its gasping for air. Everything else in there is perfectly fine though

Is your water well oxygenated / poor water quality can cause a Fish to gasp for air.
Do a 30%-40% water change/ fish should improve.