I think it's a good idea to mention it to the pdoc. I get intrusive thoughts like this and usually find it worth talking to both my therapist and/or pdoc. Sometimes a temporary increase in meds (in my case, antipsychotic), even if it's just for a few weeks, can help me get a better handle on it, if it doesn't go away on its own. It is good though that you have some insight and are looking out for "warning signs" to make sure nothing gets worse. Sometimes I debate whether I should just let a symptom pass, or take action, but I think it's better to be safe, rather than sorry.