My partner is pregnant and has asked what type of blood I have as She has negative and might need an injection at 28 weeks. Is this true or is she asking my bloodtype to find out if I am the father??

If she wants to know if you are the father... she is going to have a DNA test done after the baby is born... and you can't refuse.

But there is a medica reason she wants to know your blood type... or it will cause complications.