On Rosh Chodesh we have four aliyos by Krias HaTorah.
Rosh Chodesh fell out on Monday and by mistake it was read by the first aliyah of Kohen the Parsha of that week. After the aliyah was finished the tzibbur realized this. What should be done now. Should they read only 3 more aliyos with the Kriah of Rosh Chodesh (and divide it appropriately -- thus will come out with 4 aliyos) Or should they read 4 more aliyos with the Kriah of Rosh Chodesh (and come out as having 5 aliyos.) Please provide sources.