Rhesus negative blood type

Hi everyone 👋 I’m 7 weeks pregnant with my second baby, I’ve been spotting/had bloody discharge every day for a week now. I think it’s normal as I did have some spotting with first baby but my concern is that I feel that I should be getting the anti D injection (I’ve had a private scan to confirm a heart beat and also baby in the correct place etc) with my last pregnancy they administer the injection at 28 weeks and I was told this is because my body takes that amount of time or longer to create the antibodies which my body could release to fight the baby. My fear is that this time round my body has the anti bodies ready to release and could be fighting this baby. The policy of the nhs is not to administer the injection until after 12 weeks (assuming the reason for this is because they don’t view the pregnancy as viable until such time) Has anyone else had any experience of this? I find it cruel to leave me to worry.