Early cup use when TTC?

So, Long question short(ish), has anyone here, who uses menstrual cups, had any experience with or asked their Dr about wether it is safe to have a menstrual cup in when pregnant? I ask because I usually put my cup in before my period starts, like I'll start putting it in the day before I'm due, obviously taking it out for a quick clean and putting it back as per proper use, but I do this just in case I start early and so I don't have to mad dash when it starts. But I just now thought, is this actually safe to do because any cycle I could actually get pregnant, like right now I'm CD30 if I'm not pregnant I should start AF today, If I am pregnant I won't, but I put my cup in last night, if I am pregnant will having it in do harm to the pregnancy, I'm currently just getting milky white CM still.