hi, its very common for placentas to be low lying. the fact that it is only half covering your cervix means that there is a good chance of it moving up in the third trimester. if it doesnt then u will need to have a c section. i had a grade 4 previa which meant that it covered my whole cervix and i was unlucky that it didnt move. i googled previa's when i first found out i had one so that i knew what to expect. try not to worry tho. i am happy to answer any q's if u have any just pm me. good luck