bleeding nipple - pump suction too strong? - lifepo4 battery pack 12v

EP-
I have been traveling in Japan for 15 weeks now and recently, only 10 minutes to alleviate the problem of not being able to pump water for more than 8 hours.
Maybe I used too much force on the manual pump because I was in a hurry and wanted to go out as much as I could and was shocked to see milk and blood spray into the bottle --
Worse than strawberry milk, more like watermelon juice.
The blood is not coming out of my breast because I can clearly see the white milk flowing out together with the blood from another source.
Will suction be too strong?
This happened about 3 days ago, today I used a pizza with a battery pack and again noticed blood on the tip of the nipple but not in the milk.
The battery pack is 12 v while my pizza is a 9 v pump.
Is my battery pack wrong?