Can I get pregnant when my uteris is full of cysts an still have a period?

Not sure. You need to have your uterine diagnosis clarified. We usually do not describe 'cysts' in the uterus. You need a specific diagnosis of fibroids or polyps. A sonohysterogram might best define your diagnosis and your treatment plan. You still can have periods with either diagnosis. Polyps are easily removed. Fibroids, depending on their location & size may be a more significant surgery.
Yes. Fibroids or miomas are benign grows of uterine muscle. Ladies with fibroids may get pregnant but depending upon the size, number and location may run some risk of miscarriage or premature labor. Ovarian cysts or nabofian cysts of cervix are something totally different. Pts. Who have periods with ovulation could be fertile (you may get pregnant).