First thing I would re-sex them or have someone else confirming the sex for you.

Because your "female" has locked with another male before does not guarantee it is a female

I had what I thought was a female (did not sex upon arrival) placed "her" with a male and had locks placed "her" with another and had a fight, which made suspicious, I than sexed "her" and found out "she" was a he.

Male and female while rare have also been known to fight however fighting does not mean your female (if a female) is gravid either.