I'm so sorry for your loss OP. It was a genuine loss and you have every right to feel grief.
'Chemical pregnancy' is just a nickname given to an early miscarriage (before 5 weeks). That's all. It's not some special different process or special type of miscarriage. It's just a particularly early miscarriage!
You were pregnant and you have experienced a miscarriage. Your grief and loss are very real!
On a side note if you were 5.5 weeks pregnant this isn't even classed as a chemical (because you're over the 5 weeks mark) but I feel that's besides the point in regards to the grief because your grief is entirely valid either way.
I would keep your tattoo for now as everything is really raw and you may like to keep it later. See you how you feel. It's a lovely idea and I think you may well like to keep that with you long-term.
When we see those 2 lines on a test we feel an instant connection. We imagine a future for that child. All the pregnancy milestones (things like ooo I can find out the gender around my birthday/xmas - stuff like that) and we think of our due date, the child's first birthday, their name, what they will be like. When we will start mat leave. All sorts. Then when it ends we lose that entire imagined future. It's honestly absolutely heartbreaking and anyone who mocks that grief is sick in my opinion and certainly doesn't understand.
Please don't feel your grief is misplaced! My heart goes out to you as you're clearly really struggling. As you can probably tell I've experienced loss and I really do understand!
Also in regards to the stats and things like that, you have to remember that a lot of women are falling pregnant who aren't actively trying or testing. That's why they say the figure is so high. Such women may have discovered a faint positive if they had tested but because they're not trying or testing they're non the wiser when their period comes as usual (or a day or two late). It's only those who's period is a week or so late, or they experience symptoms that may eventually test and stumble across a very faint positive, but they may just disregard it as faulty when their period comes straight after . Remember this is women who aren't trying/testing/hoping. They probably won't think too much of it all.
Then there's the smaller subset of the population who is very actively trying to conceive AND testing early (before or around period). Even some of those may disregard a faint line as an 'indent' and think nothing more of it. So yes 'chemical' pregnancies may be way more common than we all realise, that's what they mean.
A lot of people say they would rather not even know and therefore dont test early and that's a personal choice. Some would always like to know. I would say personally I would like to know but thats partly because I've known someone have chemical pregnancies most months and it indicated a serious issue with DNA fragmentation in the sperm! But that's not the norm.
How you chose to move forward in regards to future early testing and your tattoo etc is your choice but please only do what feels right for you rather than feeling pressure about how you're 'supposed' to feel.
Your grief is real!
Sending love ❤️