Many many times you can get lumps in lymph nodes which are sited all over your body, in your head, neck, arm pits, abdomen, groin, your whole body is jammed pack full of them. When you get an infection they do their job by gobbling up infection as infection control centres but in the process they can swell up a bit.
I'm not sure how you found this little lump, whether by chance (it could have been there ages doing nothing) or by regular checking (well done you for keeping an eye on the 'normal' for you)
Either way do delight your doctor by getting it checked out as soon as tomorrow - Monday morning.
Ring, make an appointment (they will probably do a ring back) Someone will invite you for an appointment and take a look.
They will probably say 'oh it's all good, just a reaction to an infection' Then you might feel cheated for having been worried and stressed out so much unnecessarily.
A very quick check after that is to take a very small needle biopsy (just like getting a Covid jab) The lab staff will look at the cells under a microscope and tell you - yes inflammation as we thought or there are some suspicious cells there. If it is the latter they will say ok we need to have another look.
So right now you are stressing and worrying? I don't know why you are asking everyone else about what it might be because they can only guess and so can we. But none of us can give you the information you want to hear. You can do something about that - take your doctors advice. Whatever it is diagnosed to be will be outside of your control - because it is as it is. So you just have to take it a step at a time and wait for each stage. You will keep on living in between; life does not stop just because get a small lump and a doctors appointment.
The probability of it being something more serious like a cancer of any kind is very slim given your age. However you will be a joy to the medical profession if you get it checked early so please do it. The emotional pain in your head from worrying is far far worse than any physical pain you might experience and you are taking responsibility for your own health. That is a huge step (well done)
The plan is to take each stage as it arrives. No over thinking. Deal with each appointment as it arrives and do not look too far ahead. Reassure yourself you are doing everything practical that you can so there is no point wasting energy about 'what if's' Get the results, get reassured and you can get back to full living not stressing.
Please try and find someone close to you that you can confide in and talk to them about your health worries, share the worries and be there for you.
But with this one - you need a doctor to have a look and get it checked?