It has been helpful, since I view social situations differently with ASD, to try and understand human behavior from the perspective of an anthropologist. A lot of people are really uncomfortable with silence, especially around new people. At least in the United States, it is customary to engage in small talk (especially for women) and express appropriate mannerisms to put people at ease. This shows people you are safe, you can be trusted, you can get along with them. Failure to engage appropriately can make people feel tense, awkward, uncomfortable around you. They dont know how to read you and people dont like that. Your behavior is deviating from their typical interactions and it sets off alarms in some peoples' heads.
Unfortunately for folks like us, almost everyone you meet will expect you to be pre-wired with the same social instructions. There is something called neural mirror receptors in the brain, which almost acts like a telepathy to intuitively know what and how to talk to others. I dont think folks like us possess these, or they dont operate the same.
It feels like being trapped in a corner with small talk; damned if you do, damned if you dont. Force yourself to talk, risk making things weird, uttering non-sequiters, confuse your audience and forever cast yourself in social stigma in their eyes. Dont talk, you are creepy for being so quiet. Disclose your condition, that's another handicap to be ostracized.
In summary, being seen as weird for being quiet is unavoidable in all circumstances, lest you trade out the silence for forced conversation. Practice will help, but you'll want to do so with people you trust and are already on good terms with, people who are understanding and nonjudgemental. You'll have to develop a thicker skin, you'll probably always be different and will have to love yourself more than strangers or people who dont matter may naysay about you.
Best of luck!