Hi thanks for your question
Your are using multiload device for contraception
Your partner feels it, Yes normally your partner can feel its thread, but not the coil, as coil is inside the uterus
and only thread comes out from the uterus and can be felt in vagina.
Yes it can migrate from the uterus and can come dawn from uterus into cervix
and vagina, where your partner can feel it.
Your test came positive (you have not mentioned which test, probably pregnancy
test), then disappear,(again not mentioned ,what disappeared,).I presume the positive bar on pregnancy kit, which can happen sometime..
It is better for you, to get your pregnancy test from a laboratory.
Pregnancy can occur while multiload in place.
In cases where multiload get migrated,chances are more to get migrated.
As ,your case may be.
Hope I answered all the queries.