df.pct_change() not working as expected
It appears that pct_change is handling signs wrongly! 

```python
df['% Change']=df['A'].pct_change().fillna(0)*100

```
#### Problem description

#### Current output from dataframe
index | A | % Change
1 | -482.411 | 0.000000
2 | -357.073 | -25.981580
3 | -506.110 | 41.738524

#### Expected Output from the dataframe
index | A | % Change
1 | -482.411 | 0.000000
2 | -357.073 | 25.981580
3 | -506.110 | -41.738524



#### Output of ``pd.show_versions()``

INSTALLED VERSIONS
------------------
commit           : None
python           : 3.7.3.final.0
python-bits      : 64
OS               : Windows
OS-release       : 10
machine          : AMD64
processor        : Intel64 Family 6 Model 142 Stepping 10, GenuineIntel
byteorder        : little
LC_ALL           : None
LANG             : None
LOCALE           : None.None
pandas           : 1.0.1
