Need honest opinion

There is no way, no how, not possible for someone including a dermatologist with degrees from Harvard, Princeton etc to tell you a mole is or is not melanoma without doing a biopsy. With that said there are certain indicators that make a mole suspicious, which leads to a biopsy. My former dermatologist told me when I showed her the mole on my arm "don't worry about it my son has the exact same mole". A couple years later found out It was melanoma and had progressed to stage 3b. I go to Mayo now and the dermatologist there told me if you go to a dermatologist and have a suspicious mole and they are not reaching for a scalpel to biopsy it then fire them and find a dermatologist that will. It is your health and not theirs-you have to take ownership of your body and direct your care or you may find yourself unhappy with the results. My highly uneducated opinion is to get a biopsy if you are concerned

No… change doesn't guarantee melanoma. It is one of the ABCD and E that derms should be looking for in a mole (or in this case… moles). You are young, so it is possible to have "Evolution" with moles and even new mole growth still. But… change is an indicator that something should be investigated more closely. Personally, I'd rather err on the side of caution, and know through pathological certainty whether it is "something" or "nothing".

Do you have a family history of melanoma?  Are you an avid sun worshipper?  As the other poster said, you are young and moles just show up.  When you post on a melanoma board, you are going to get advice that is biased because we all have melanoma.  However, in the big picture, melanoma is still fairly rare and if you don't have a family predisposition or if you aren't an active sun worshipper or tanning bed user, your risk is still pretty low and your anxiety might be out of proportion to your risk.  I'm not saying that you shouldn't get things checked but if you've had derms look at the lesion and they aren't concerned, then that's a pretty decent indication that things are ok.  Here is what I suggest.  Take very good pictures of the lesion NOW.  If it continues to change, you can go back to a derm and show how things have progressed.  That type of documentation will help facilitate a biopsy.  If the lesion doesn't continue to change, it's not going to be melanoma.  And as someone else said, even changing lesions don't have to be melanoma – in fact, most aren't.  But they are more suspicious.  You can get new moles up until the age 30ish and new and like other moles is perfectly fine.  New and "ugly duckling" is more concerning.  Again, not any guarantee of melanoma – I just had a new and ugly duckling mole removed and it was totally benign.