Spacing After a Period
Use one space after a period (or other punctuation mark at the end of a sentence) when writing in APA Style. However, if your instructor or non-APA publisher has other requirements (e.g., to use two spaces), follow their specifications.
Spacing after punctuation marks is covered in Section 6.1 of the APA Publication Manual, Seventh Edition
This guidance has been revised from the 6th edition.