According to Bpip your password was changed 3 times since registration which the last one was done today using your email address.
If your are worried of security, then try checking your login device who have access to it, increase your security measures, and don't save your login in browsers. If this was actually a hack attempt you might not be lucky next time to use your email and reset the password because it will be removed and change completely.
I changed today few minutes before making this post as I was not able to login. I am sure that I did not change password since long time before this. I remember changing it once more few years back and that time also someone guessed , changed my password and made 1-2 unwanted posts from this profile.
They got access to your account and did not change your email, it means they don't want to take ownership of the account.
But it is risky someone making posts with your account. The person might use your account to spread malware or plagerise, and you know the consequences. You will lose your account. That will be a big challenge to you because you will first have to appeal for ban and then prove ownership of the account.
Since you still have access to the account, I think you should rather create a new email, change the email of the account and reset your password before you will be totally compromised.