Actually, never proof it, if u never try it, if You had a chance on buy it.

Or maybe You can try this alternative :

You can read a lot about how to prolong Lithium battery at here : http://www.batteryuniversity.com/parttwo-34.htm

Some conclusion stated :

A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.

Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.

Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.

Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing dates. Do not buy old stock, even if sold at clearance prices.

If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the battery at 40% state-of-charge.

Just opinion, let's discuss

it's probably difference around 2mm. The battery is "fat". I don't know how to call it in English. maybe опухший means this same
It was more slim before. You'll know what i mean. BTW. my battery isn't original (probably), and the BS one will work longer?

About "pregnant", yes it's almost the same meaning as You said Huteusz. To get sure Your battery really flat, just put in on the plain surface (ex : floor) than swing it, if it's circling then i can say it was "pregnant".